UNITED STATES OF AMERICA. 








vjieyataA^ c^/^^""^^^ 



U.S. DEPARTMENT OF AGRICULTURE. 

B0EEAU OF ANIMAL INDUSTRY. 



THE 



ANIMAL PARASITES OF SHEEP. 



BY 



COOPER CURTICE, D. V. S., M. D. 
i 

PUBLISHED BY AUTHORITY OF THE SECRETARY OF AURICULTURE. 



2^(?> 



WASHINGTON : 

GOVERNMENT PRINTING OFFICE. 
1890. 



TABLE OF CONTENTS. 



Paga 

Letter of transmittal 7 

General remarks 9 

Parasites of the nose : 

Grub in the head, (Estrus ovis, Linn 25 

Parasites of the skin : Phthiriasis, Acariasis. 

The sheep tick, Melophagus ovinus, Linn 39 

The sheep lonse, Trichodcctes splueroeephalus, Nitzsch 45 

The goat louse, Trichodcctes limhatus, Gervais, and Trichodectes climax, 

Nitzsch 49 

Scab insects: Acariasis, itch, scab. 

Head scab, Sarcoptes scabiei, de Geer, var. ovis 53 

Common scab, Psoroptes communis, Fiirst, var. ovis 56 

Foot scab, Chorioptes communis, Verheyen, var. ovis 65 

Parasites of diverse organs : 

The pentastoma, Linguatulatauiioides, Rud 69 

Immature tape-worms : 

Bladder worms, Twnia marginata, Batsch 72 

Gid or staggers, Twnia cwnurus, Kiich 83 

Hydat'ula, Tania echinococcus, V. Sieb 86 

The mutton measle, Twnia tenella, Cobbold 87 

Parasites of the alimentary canal and appendages: 
Adult tape- worms: 

The fringed tape-worm, Twnia fimbriata, Diesing 89 

The broad tape-worm, Twnia expansa, Rud 113 

Liver-flukes : 

The large liver-fluke, Distoma hepaticum, Linn 127 

The small liver-fluke, Distoma lanceolatum, Mehlis 137 

The stomach worms : 

Amphistoma conicum, Zeder 138 

Stronqylus contortus, Rud 141 

Intestinal round worms : 

Introductory remarks 145 

Slrongylus filicollis, Rud 146 

Strong ylus ventricosus, Rud 149 

Ascaris lurnbricoides, Linn.... 151 

Dochmius cernuus, Creplin 155 

Sclerostoma hgpostomum, Diesing 161 

The nodular disease of the intestine, CEsophagostoma Colmnhianum, n. sp 165 

Trichocephalus affinis, Rud ^ 181 

Parasites of the lungs: 

Introductory remarks 185 

The hair lung- worm, Slrongylus ovis-piilmonalis, Diesing 186 

The thread lung- worm, Strongglus Jilaria, Riii 201 

3 



INDEX OF ILLUSTRATIONS. 



Plate I. (Estrus ovis, luiumvus 34 

II. (Estrus oins, in ^5iullse^ of the bead ~ 36 

III. (Estrits oris, in nasal cavity and sinnses of the head 38 

IV. Melophayun ovinus, Liumvus 44 

V. Trichodecies spharocephahts, 'Nitzsch 48 

VI. Trichodectes limhatus, Gervais, et T. climax, Nitzsch 52 

VII. Psoroptes commmnis, Flirst., var. oris. Adult 66 

VIII. Psoroptcs communis, var. ovis. Young 68 

IX. Tania 7na)<jinata, Batsch 80 

X. Ta-nia margtnata, in the liver S2 

XI. Tania ienella, Cobbold, T. cmmrHs, Kuchenmeister, et T. ech- 

inococcus v. Sicbold •- -. 88 

XII. Tivniafimhriaia, Diesing 110 

XIII. Toniafimhriata, original figures of Diesing 112 

XIV. Twniaex2)ansa,Ji,nt\ol\>\\\. Adult 124 

XV. To nia expansa, young stages 126 

XV^I. Distoma hepaiicHm,'L\nnivus 136 

XVII. Lliifjitatiihi Uvuiodes, Kudolphi, Amphistoma conicum, Zeder, 

et Distoma lanceolaiiim, Mehlis 140 

XVIII. Strovgylus contortim, Rndolphi 144 

XIX. Strongylufs filicoUis, 'Rn^\o\\^h.\ 148 

XX. Strong yhis ventricosKS, Rudolphi 150 

XXI. Jsearis Jumbricoides, Linuii'us 154 

XXII. Dochmius ce7-nuns, Creplin 160 

XXIII. ScJcrostoma hypostomum, Dujardin 164 

XXIV. (Esophagostoma Cohimhianum, Curtice. Adult 174 

XXV. (Esophagostoma Cohtmhiarium, youug stages 176 

XXVI. (Esophagostoma Cohiynhianum, in the intestinal coats 178 

XXVII. (Esophagostoma Columhianum, in the intestinal coats 180 

XXVIII. Trichocephalus affinis, Rudolphi 184 

XXIX. Strongylus otns-pulmonalis, Diesing 192 

XXX. Strongylus oms-pulmonalis, in the lungs 194 

XXXI. Strongylus ovis-pulmonalis, in the lungs 196 

XXXII. Strongylus ovis-pulmonalis, in the lungs 198 

XXXIII. Strongylus ovis jnilmonalis, in the lungs 200 

XXXIV. Strongylus filaria, Rndolphi 210 

XXXV. Strongylus filaria, in the lungs 212 

XXXVI. Strongylus filaria, in the\nng% 214 



LETTER OF TRANSMITTAL. 



Washington, D. C, April 2J , 1 800. 

Sir: I have the honor to submit herewith a report upon the para- 
sites ofsheei), whicli has been prepared with much care and will prove 
of permanent value to all owners of this class of our domesticated ani- 
mals. The information heretofore attainable on this subject in the 
United States has been fragmentary and in many cases unreliable, 
although the parasitic diseases of sheep are among the most frequent 
and seriouir' maladies by which this species of animals are affected. 

It has been the aim in the [)reparatiou of this volume to make the 
descriptions and the illustrations so plain that any one will be able to 
identify the parasites which he may find in his flock, and yet the sub- 
ject is in some of its aspects so technical that it could not be presented 
entirely in popular language. Tiie technical descriptions which it is 
deemed necessary to insert have, however, been placed in small type, 
and those not interested in the characters by which the species are 
identified can omit such paragraphs. The symptoms and appearances 
I)resented by diseased animals and the treatment of the diseases have 
beeuigiven at considerable length, and these will be read with interest 
by all who desire information on this subject. The illustrations are a 
])romiuent feature of the work, haviug been drawn and lithograi)lied 
with the greatest care, and every attention given to make them accu- 
rate in tbeir most miinite details. Nearly all of these are original and 
were drawn from nature. 

The nodular disease of the intestines, together with its cause, is de- 
scribed for the first time in these pages. This disease is common and 
wide-spread, but its cause and nature were mysterious until they were 
discovered through the investigations of this Bureau. We have here 
once again a demonstration of the value of systematic, scientific in- 
vestigation of the diseases of animals, for the results obtained by the 
studyof this malady are among the most interesting contributions of 
modern research. The facts obtained in the investigations of the fringed 
ta{)eworm and the hair lung- worm are also of more than ordinary in- 
terest. 

Tlie subject of i)anisites and parasitic diseases is one of great impor- 
tance, and must become more prominent as the number of domesti- 
cated animals in the country increases and the pastures become more 

7 



8 

limited ia comparison with the tlocks wliicli graze upon tlietn. Under 
such conditions parasites multiply more rapidly, and their ravages be- 
come more alarming. For this reason the time has come when we must 
pay more attention to these organisms and study more assiduously the 
means of controlling them, if we would preserve that healthfulness and 
vigor for which the animals of this country have heretofore been noted. 
It is hoped that the systematic treatment of the subject presented in 
the accompanying volume may assist in accomplishing this object. 
Very respectfully, 

D. E. salmo:n^, 

Chief of the Bureau of Animal Industry. 
Hon. J. M. Rusk, 

Secretary of Agriculture, 



ANIMAL PARASITES OF SHEEP. 



GENERAL REMARKS. 

In 1782, Goeze, a distiuguislied German naturalist, wrote : "Among 
all mammals except the horse, the sheep appears to be most harassed 
by worms." He thus called attention at that early period to the great 
abundance of ovine parasites, an abundance which have transmitted 
their posterity in comparatively undiminished numbers. 

The presentation of all the facts now known concerning these para- 
sites, their structure, their life histories, the injuries they cause, and 
the methods of prevention and treatment, together with such new ma- 
terial as may have been learned concerning them, needs no apology to 
the sheep owner, for he is alive to the fact that the majority of his losses 
is due to these parasites. The sheep industry of the United States 
embraces the product of 42,599,079 sheep, valued at $90,040,369.* De- 
pendent on these sheep and their products are an army of men and their 
families, from the flock-master and his help to the consumers of the flesh 
and the manufacturers of the fleece. Add to this the value of the plant, 
which is dependent on the sheep industry in all of its ramifications, and 
there results an accumulation of many millions of dollars, a value which, 
from a business stand-point alone, should cause the Government to 
foster and to protect it from every source of injury. 

As the whole growth of the industry is dependent on the health and 
vigor of the sheep, it follows that whatever tends to produce a better 
condition or ward off threatening disease from them is for the benefit 
of all interested in and dependent upon the success of the industry. 
The parasitic diseases — those produced by the animal parasites of 
sheep — are, if we may judge from observation and the letters* of inquiry 
directed to this Bureau, the chief source of losses, and if in any way this 
bulletin may result in promoting a better knowledge of these too little 
known pests, and in teaching facts which will lead to better care and 
treatment of the flocks as regards hygienic prevention of diseases, the 
cost and labor laid out upon the work in its various details will be well 
expended. 

Particular attention has been devoted to illustrating each species of 
parasite, and, so far as possible, the lesions of the disease produced by 

* United States Department of Agriculture, report on numbers and values of farm 
animals, January, February, 1889, pp. 5 and 6. 

9 



10 

it. lu the illustrations of the species certain features which present 
specific differences have been constantly drawn. Peculiar features of 
anatomy and development have also been illustrated. The entire de- 
velopment of any species from the unimpregnated ovum to the adult 
form is not illustrated, but one species may show the developing ova, 
another the embryo, and still another small and adult forms, and thus 
the entire development of many of the species can be well understood. 
Especial attention has been devoted to representing certain organs of 
economic importance, *. e., those orgjins which are immediately con- 
cerned in injuring the tissues of the sheep. The majority of the draw- 
ings were made from nature by Mr. W. S. D. Haines, and the others by 
Dr. George Marx, both artists connected with this Department. The 
excellence, of their work shows for itself. Where material for original 
illustration has been unavailable, figures chosen from the leading 
text-books on the subject under consideration have been copied, and 
due recognition of the source acknowledged in the description at- 
tached. For the accuracy of these drawings the author alone is respon- 
sible. He believes that all the anatomical details are accurate, but such 
is the difficulty of seeing the minuter details that some of the latter are 
omitted. As their presentation belongs i)roperly to a more specific 
investigation than tbis their absence will scarcely be noticed. It has 
been the constant endeavor of both the artists and the author to make 
technically perfect drawings, aiul at the same time present the subject 
so clearly to the eye that not only a novice may, by the aid of a small 
magnifying glass, be able to determine the species, but that the scien- 
tist may also use the work profitably in subsequent investigations. 

The text devoted to each species is intended to contain a general 
description of the parasite, its life history, the way it causes disease, 
the disease produced and mode of treatment, both preventive and re- 
medial. Many of the specific descriptions are technical. To the be- 
ginner, who can identify the species by careful comparison with the 
figures, these are unnecessary, but as he advances in their study the 
meaning of the technical descriptions will become more apparent and 
useful. In a work of this character such technical specific descriptions 
are unavoidable. To the scientist they are absolutely necessary. 
Wherever possible the complete life-history of the parasite is described 
and illustrated ; unfortunately, however, the species whose life-histories 
are positively known are too few. Although the life-histories of the 
majority of the worms seem very evident, still the evidence upon which 
they are based is not deemed entirely conclusive by scientists. So skep- 
tical are the majority of this guild that rigorous proof alone seems to 
satisfy them, and this is particularly the case when the views set forth 
in regard to either of the si)ecies are at variance with pre-existing 
opinions. 

Rigorous demonstration of the various stages in the liie-history of a 
parasite demands that its eggs or embryos shall be fed to an uninfected 



11 

host (sheep in this case), and the parasite be found in it subsequently, 
at a stage of growth corresponding to the time which has elapsed dur- 
ing the experiment. The conditions necessary for raising embryos, for 
procuring uninfected sheep and for keeping them from outside sources 
of infection, are many and difficult to fulfill. Up to the present time, 
with few exceptions, infection has been secured in the experiments only 
by excluding or regulating certain of the conditions surrounding sheep. 
These conditions are such that, although the problems in each case 
have not been absolutely proven, there is much probability that the life- 
history of most species is well determined. In describing the injury 
wrought by the parasite and the resulting disease, technical descrip- 
tion has been avoided as much as possible, in order that the work may 
be rendered more valuable for farmers and ranchmen, who have but a 
limited knowledge of the terms used in medical literature. These de- 
scriptions are, on this account, necessarily imperfect from a scientific 
point of view, but it is hoped none the less efficient for the purpose* 
A careful study of the various diseases will show that the irritations 
set up and the lesions resulting therefrom are mainly due to mechan- 
ical causes, whatever be the organ attacked. Certain of the dis- 
eases, however, seem to be aggravated by nervous or reflex irritation 
induced by the parasite, while others are hastened by a loss of blood or 
nutritive material abstracted from the host by the parasites. 

The diagnosis of parasitic diseases is always determined by finding the 
parasite or its eggs. The quickest and surest determination for inter- 
nal parasites is made at a post-mortem examination. For intestinal 
parasites many authors recommend the examination of the dung. This 
method has not been verified by experience, but appears to be tedious 
and difficult, and a method better adapted to experts than layman. 

There are certain symptoms from which one may infer that sheep are 
infected with parasites. A large part or all of the flock is affected and 
the symptoms shown by the different individuals are similar. The ap- 
petite is generally good, but individual members present a poor, stunted, 
hidebound, bloodless, big-headed, pot-bellied appearance. Other local 
symptoms, depending on the organs affected, are present. The most 
positive characteristic is to find that a number of sheep raised together 
are affected in the same way. From these general symptoms those de- 
pending on climatic changes, and irregularity or insufficiency of food 
and water, must of course be excluded. The sheep owner who discovers 
weakness among his lambs should not wait until one of them dies before 
he endeavors to make a diagnosis, but should undertake to diagnose the 
disease in the earlier stages by sacrificing one or more of the worst 
affected, and thus gain time in treating and preventing the extension of 
the disease. By waiting for the disease to develop he allows the lambs 
to grow poorer and weaker, and when action is finally undertaken it is 
upon patients which are, in many cases, already too weak to stand 
vigorous treatment, and which can in no way profit by preventive 



12 

measures as they should. The lambs examined can, if the meat is not 
too poor and watery, be used on the table without harm to the consumer. 
If the animals are at all feverish, as is the case in the later stages of 
disease, the carcasses should be thrown away. It is in the beginning 
of the disease that treatment, both hygienic and medicinal, is needed 
and produces its best results, and therefore an early diagnosis and de- 
termination of the malady is fully as essential as in the more virulent 
bacterial scourges. 

Tiiough the treatment advised in a work of this character should be 
its strongest point, yet it is to be regretted that such is the state of 
knowledge of the life-history of these pr.rasites and of the practical re- 
sults of medicines used in combating them under the conditions in 
which sheep are held on the pastures, that it is felt that this field is yet 
to be properly entered and worked up from an experimental stand-point. 
The subject appears, as yet, to be in an empirical stage. Although the 
best recipes have been compiled and presented, they appear to be old 
and hackneyed to one who has been enabled to trace the same recipes 
from book to book. Indeed, some of those presented, which contain 
inherent virtues, come from countries where sheep-ranching is unheard 
of, and seem to be sufficient only in the closely settled communities 
where labor is cheap and where time can be devoted to saving property 
even though the value is not great. The medical treatment of large 
flocks should be investigated from a broader stand-j)oint than any yet 
taken. Our insufficiency of knowledge on these points arises from the 
small value of single animals and the hesitation of people to seek the 
aid of skilled veterinarians until they find that they are unable lo treat 
the disease themselves. The great benefit in doctoring animals wliose 
Individual worth is but a few dollars lies in the treatment of numbers 
at a time, and in making an early diagnosis of the disease. Those who 
have large and valuable flocks should watch their lambs for the earli- 
est symptoms, and then if there is a skilled veterinarian available ob- 
tain his services. Oftentimes the family doctor can and will give advice 
that will materially assist, for his knowledge of other diseases, their 
symptoms and lesions, and of the use and effects of medicines, make 
him the most available authorit^^ in the absence of the veterinarian. 

Upon the hi/gienic treatment, i. e., upon the care and attention the 
flock receives, depends in great measure its health and good condition, 
and the prevention of the parasitic diseases. It is out of the province 
of this bulletin to discuss the proper housing, food, and drink of sheep, 
beyond what is required for the prevention of parasitic maladies. The 
chief necessity as regards buildings and yards is that they should be 
kept clean. Periodic cleansings of wood-work and floors should be 
sufficient. Whitewashing and the liberal use of lye water for cleansing 
wood- work are desirable, and in some diseases, such as scab, absolutely 
indispensable. In the care of yards an economic management of the 
manure is to some of prime importance. It would seem that a mixture 



13 

of this manure with lime in the compost heap, and a frequent cleansing 
of the yard, would be far better, so far as the sheep are concerned, than 
to allow it to accumulate. The lime would not only serve to kill the 
eggs of parasites in the manure, but would add fertilizing material to 
it. Manure so treated would be a better fertilizer, and would also be 
less apt to infect sheep when spread upon the fields. The compost 
heap should never be where the liquor from it can be washed by the 
rains into water which the sheep drink. As the manure from these 
yards may prove the source of infection, sheep should never be pastured 
on fields recently enriched with it, unless there is absolute certainty 
that the previous treatment of the manure has destroyed all the em- 
bryos of the parasites. As frequently urged in the text, every means' 
should be taken to supply sheep with pure water. Although experi- 
ments show that sheep have other means of getting parasites than from 
the water they drink, yet this is at times a very fertile scource of infec- 
tion. The use of drinking-troughs into which water runs or is pumped, 
and rapidily running water, seem best suited to meet the requirements. 

The grain food should be fed from cleanly swept troughs or floors. 
Hay should be put in racks, as feeding from the ground is not only 
wasteful but tends to infect with parasites. Salt should be supplied in 
boxes placed where sheep can have ready access to it. The mixture 
of a small proportion of finely powdered sulphate of iron with the salt 
is allowable at times. 

Pastures, which are ordinarily uncared for further than to provide 
fences for securely confining the sheep, need careful supervision. Wet 
swails, bogs and swamps should either be fenced out or drained. Past- 
ures which are overstocked, and in which a flock of sheep is kept con- 
tinuously, are the most fertile sources of infection. Not only do the 
sheep become more frequently infected where they are compelled to eat 
the grass close to the ground, but the chances of their being compelled 
to graze on an infected area are largely increased by keeping them 
ranging over the same ground of limited area week after week. Old 
sheep stand such treatment much better than young ones. For the lat- 
ter, those fields which have not been pastured on by older sheep are 
better. The practice of feeding the sheep over fields from which the 
crops are removed is a good one, not only for the sheep but for the 
fields. These remarks, of course, apply more strictly to fenced farms 
and not to unfenced sheep ranges, but even on these certain portions 
of the range can be reserved for the lambs. The practice of allowing 
lambs, after they are old enough to wean, to feed after older sheep is 
also a source of infection. 

The relation of the dog to sheep husbandry is too imiiortant to be over- 
looked. Were it not that the definition of parasite excludes such ani- 
mals as can be considered beasts of prey, the dog would be placed at 
the head of the list of j^arasites as being the most destructive. Though 
this be unmistakably apparent to a large majority of sheep-owners, 



14 

there are mauy who believe that the (lo^ is man*s most faithful friend 
and that ho is of great use even on a sheep farm. It is unfortunate for 
the dog tliat the mass of testimony on this subject is against him. It 
is not from the stand-point of the dog as a beast of prey, however, that 
this work is written, but it is from the more technical stand point of the 
(loif as a carrier of parasites dangerous to sheep and man. In the list of 
parasites of sheep there are at least four which are common to the dog 
and sheep, viz: Ta-nia marginata, Batsch; T. co'nurus, Kiich.; T. echi- 
nococcus, V. Siebold, and Linguatula toenioides, Rud. The last is rare, 
and in justice to the dog should not be used against him, although it 
may subsequently aiford as damaging evidence as the other si^ecies. 
By referring to the descriptions of the other three species it will be 
found that dogs harbor in their intestines the adults of these species, 
and that they scatter the eggs of the parasites broadcast for the infec- 
tion of sheep. Thus each dog, harboring one or more, is a constant 
menace to the health and lives of the flocks in the neighborhood. Nor 
is this all, for man himself can be infected by at least two of these spe- 
cies — Tania cchinococcus and T. marginata — in their cystic stage. The 
former of these species produces a disease of slow development, but one 
which is nearly always fatal in results. To prevent these diseases the 
precautions prescribed in the text must be closely adhered to. A plan 
which would remove much of the loss caused by dogs by doing away 
with them entirely is scarcely practical in this country, where the ma- 
jority of these animals are owned by persons who have no direct inter- 
est in sheep. The hunting and the sheep dog are most to be feared, 
unless we except some of the fiercer watch-dogs which are kept at 
slaughter-houses and fed on waste bits. The day of the usefulness of 
hunting dogs is quite past, and their retention by sheep-men at least 
should be abandoned. The watch-dogs are nearly always chained and 
in places not accessible to sheep. 

In the range country the coyotes and prairie wolves still menace the 
flocks by killing individuals for food, and by harboring the adults of 
Twnia marginata and T. eoenums, the eggs of which they also scatter. 
In most sections, especially where a bounty is oflered for their scalps, 
the trap is remorsely exterminating them. Laws which would subject 
the mongrel curs to the same treatment would result in a great gain to 
the farming community and to their respective owners, if they be owned 
by any one. 

There are reports that the sheep can be infected by parasites from 
some of the many wild animals that still haunt the land where they 
were formerly so abundant. The examination of these little quadru- 
peds to ascertain the parasites they contain has not been as extensive 
as it should be for a broad generalization, but so far as it has extended 
it is safe to say that sheep are not infected from either rabbits, skunks, 
squirrels, woodchucks, gophers, prairie dogs, or foxes. Foxes may 
harbor some of the adult Tivnia whose cystic stages infest sheep, but 



15 

unless they can obtain the young forms of the parasites by eating the 
viscera of sheep they woukl be very unlikely to be infected with adults. 
It is also reported that rabbits harbor the cystic form of Taenia margin- 
ata ; but this statement has not been corroborated, as the rabits ex- 
amined contained the cystic form of T. serrata. If rabbits should be 
Ijroven to harbor the cysts of T. marginata then the danger wonld 
arise, not from them, but from hunting-dogs which eat the rabbits and 
the cysts they contain, and harbor the adult jiarasites that alone are 
the source of danger. The possibility of infection b^- parasites from 
deer is too small to be considered as an economic question, owing to 
the great scarcity of these animals. The antelope {Antilocapra ameri- 
cana, Ord.) may be a bearer of many of the same species of parasites as 
the sheep, but they also are becoming too few to be considered as n 
source of danger. In short, it is futile for the flockmaster to consider 
these sources at all while his own flocks are infecting his fields, and his 
dogs are constantly assisting them. Could these sources of infection 
be controlled, there would be no need for him to regard the wild ani- 
mals as his enemies. 

Ln purchasing sheep particular attention should be paid to the gen- 
eral appearance and past history of the flock from which the purchase 
is made in order to avoid parasitic diseases. Before adding recent pur- 
chases to flocks they should all be thoroughly dipped to kill external 
parasites. If they are coughing ever so slightly, the cause of the cough 
should be investigated to determine the presence or absence of lung 
worms. If some are hidebound or weak after allowing for the charac- 
ter of the season and the condition of pasturage the i^ossible presence 
of intestinal parasites should be next considered. It is not very prob- 
able that there are any farms free from all parasites, but there are many 
that are free from a considerable portion of the species which are prop- 
erly parasitic on sheep. Purchasing here and there in making up a 
flock brings all sorts of parasites together, thus infecting a farm to such 
a degree that it is difficult to get rid of them. 

The medical treatment must, of course, be sjiecially adapted to the dis- 
ease. The treatment of external parasites is effective, and well repays 
all efforts. The treatment of internal parasites may be divided in gen- 
eral into treatment for lung worms, for intestinal worms, and for liver 
worms. The last is by far the most unproductive of good results. Par- 
asites situated elsewhere in the sheep do not readily yield to medical 
treatment. 

Scab is the only parasitic disease that has been thought worthy 
of legislation. There are others that demand as serious considera- 
tion, but their importance has not yet been fully presented to the 
public. Little attention has been given to police interference in the 
management of these diseases. No doubt such interference might be 
profitably pushed further than it is in this country, especially with 
regard to scab. Not only should the highways be guarded against the 



16 



movement over them of scabby sheep, but a competent imspector 
shoukl be appointed by the State to supervise every sheep dipping, to 
compel the dipi)ing of every scabby flock, and to attend to the renova- 
tion and disinfection of the sheep-yards and walks. Every band of 
scabby sheep is a constant menace to the health of others. In this 
country there seems to be no sheep disease produced by animal para- 
sites which renders the flesh harmful to man, further than that some 
of the flesh may be less nutritious. Until the sale of meat of all kinds 
is guarded by more stringent regulations there does not seem to be any 
reason for urging police restrictions on the sale of meats of the inferior 
quality which some of these diseased lambs undoubtedly furnish. 

There are described in this volume twenty-six species of animal para- 
sites of sheep, as follows : 



1. (Estrus ovis. 

2. Melophagus ovinus. 

3. Trichodectes sphwrocephalus. 

4. Trichodectes climax. 

5. Trichodectes limhaius. 

6. I'soropies commiitiis. 

7. LingnaiuJa ta-nioides. 

8. Tivnia Jimhrlata. 

9. Ta;nia ex2)ansa. 

10. Tccnia maryinata. 

11. Taenia teneUa. 

12. Taenia cwnurus. 

13. Tcenia echinococcus. 



14. Disioma hepaticiim. 

15. Amphistoma conicum. 
13. Distoma lanceolatum. 

17. Strongyliis coniortus. 

18. Sfrongyhts fiUcoUis. 

19. Stroitgylus vcntricosus, 

20. Ascarin Ittmhricoides. 

21. Dochmius certuius. 

22. Sclerostoma h !J2>ostomum. 

23. QLsophagostoma Coliimbianum. 

24. Trichocephalus affinis. 

25. Strongylus ovis-pulmonalis. 

26. Strongylus filaria. 



Of the species described three genera — Bfelophagns, Trichodectes, and 
Psoroptes, embracing five species, 71/. ovinus, T. sjyJicerocephalus, T. cli- 
max, T. limbatus, and P. communis — are external parasites. 

The species which there is reason to think do not occur in this coun- 
try are Tcvnia ieneUa and AmpMstoma conicum. The former is consid- 
ered by continental authorities as a synonym of T. solium or T. margi- 
nata. The writer has not found Linguatula tccnioides, Tccnia ccenurus, 
T. echinococcus, Bistoma hepaticum, or D. lanceolatum in sheep, nor 
learned from authentic sourcesof any of these occurring here excei)tD. 
heimticum. The other species may eventually be found, but they will 
probably be rare. Une other species, Ascaris lumbricoides, seems to 
be a rare one in sheep. The remaining species are all more or less 
.abundant. Tamia fimhriata and (Esophagostoma Colnmhianum seem to 
be exclusively American species. The others are common to all parts 
of the world where there are sheep. Von Liustow {Compendium der 
Helminthology, 1878), catalogues nineteen species of internal parasites 
which infest European sheep. One of these, Monodontus Wedlii, Molin, 
is a synonym of Dochmius cernuus Crepliu ; another, Nematoidetim 
ovis, Diesing, is a lung-worm insufficiently described. Still another, 
Trichosoma papillosum AVedl., is a synonym of Strongylus JilicolUs, Kud. 
The remaining sixteen species are described in this volume. There are 



17 

two lung parasites of sheep in the Old World that have not been foiiud 
here, viz : Stronyylus ru/esceiiis, Leuckart, and S. ininutissimus, Meguiu. 
The former is said to occur in Germany and France, but is so meagerly 
described that it probably is not a distinct species, but a synonym of 
Strongtjlus {PseudaUus) ovis-pidmonalis, Diesing. The latter occurs in 
Algeria, is well described and figured, and. seems to be a well estab- 
lished species. Strongylns ventricosus, also a European species, has 
not, to my knowledge, been described as a parasite of sheep heretofore. 

A further comparison of the above list with those of parasites of sheep 
in other countries is re-assuring, because, first, native sheep have now 
nearly all the parasites that they can acquire in this country; second, 
that although nearly all the European species have been imported, Dis- 
toma hepaticum, L., the liver-fluke, Tcvnia .echinococcus, v. Siebold, and 
T. cceniirus, Kiich., are either very rare or else do not exist in this coun- 
try. These three parasites have been the cause of great loss among 
sheep in other parts of the world. 

The comparatively long list of parasites furnished will seem to the Eu- 
ropean to indicate that sheep in this country are more infected than 
those in Europe; but in this connection it should be remembered that 
much time has been spent in hunting for several of these species, and 
some of them are rare, inconspicuous, and do little damage. 

The following is a list of our most destructive ovine parasites: 

(Estrus ovis, L.; Psoroptes communis, Yiust.; Taniajimhriata, Diesing; 
T. expansa, Rud.; Strongylus eontortns, Eud.; Dochmius cenimis, Creplin; 
Q^sophagostoma Columhianum^ Curtice; Strongylns ovis-jmlmonaiis, Dies- 
ing ; and S. filar la, Rud. There are nine species in all, a list which 
compares favorably with that of the ovine parasites of any other coun- 
try ; for all but two species, T. fimhriata and 0. Columbianum, are com- 
mon to all countries, and these two are more than offset by the preva- 
lence of more destructive parasites in the Old World. 

On the whole, the flockmasters of the United States may be congrat- 
ulated on the good condition of their flocks and their comparative free- 
dom from both external and internal parasites. 

PARASITISM. 

Definition. — The animal parasites of sheep are those which live in or 
upon their living bodies and obtain nourishment from them. The term 
" animal parasites " is used in order to distinctly separate this group 
from the vegetable parasites which attack the living organs of sheep. 
Both animal and vegetable parasites prey upon the flocks and cause 
disease, but such are the differences between them, their eflects and the 
methods of investigating them, that an investigation of either forms a 
large field of research. 

Parasites as defined above include a large number of animals so dif- 
ferent from one another that parasitism is the only common character 
23038 A P 2 



18 

which groups them together. Though this distiuctive feature is suffi- 
cient for the present purpose, it is a very variable character, for the 
degree of parasitism manifested by each of the species varies through 
all the scale possible from the transient momentary parasites to the 
permanent. 

The animal parasites of sheep are all embraced within three great 
branches of the animal kingdom : The Protozoa, Ver^nes, and Arthro- 
poda. None of the first branch, which includes the Goccidia and Bal- 
hiana gigantea, Eaillet, are described in this volume. Examjiles of the 
second, which includes all the worms, and of the last, which includes 
the insects, mites, and linguatula, are abundant. 

The worms live, as a rule, in the open cavities of the body — in air 
spaces of the lungs, the ducts of the liver, and the lumen of the intes- 
tine. The exceptions to this rule arise from those immature forms 
which penetrate into the substance and closed cavities of the bodies, 
e. g., the bladder stages of the tape-worms and the young embryos 
of (Esophagostoma. The worms are called iniernal jjarasites. It is 
easily understood, however, that being held in the cavities of the body 
which have communication with the exterior, they are really external to 
the body tissues, and only those embryonic forms which penetrate into 
the tissues of the infested animal or host are true internal parasites. 

As a rule the insects live on the surface of the body. They are 
called external parasites. The exceptions are the larva of (Estrus avis, 
which lives in the nasal cavities, and Litiguatula, whose young stage 
infests various organs of sheep. (Estrus is usually classed with the 
external parasites, and Linguatula is in sheep truly internal. As has 
been stated, those parasites which in their young stages penetrate the 
tissues of sheep are alone true internal parasites. Even these spend 
their adult stages in the open cavities of some other host and then be- 
come true external parasites, so that no one of these parasites is, strictly 
speaking, an internal one throughout its life. That every parasite 
should be an external one in its adult stage is a necessary condition of 
its existence and of the perpetuation of its species, for it is only in the 
open cavities that they can obtain sufficient air and food, and can mate. 
From these cavities, too, the eggs and young can escape for the infec- 
tion of other sheep. The facility offered for mating and distribution 
is the most important reason. In order to avoid confusion of terms 
those parasites infesting the surface of the body will be called, in con- 
formity with custom, external parasites; the others, which inhabit the 
tissues of the body and its cavities, internal. 

Though the animal organisms that infest the living bodies of sheep 
be small, they are endowed with all the vital functions of life. All can 
move, feed, feel, and reproduce. None of the worms can see or hear. 
The insects are more highly specialized than the worms. All of them 
have in the past become so adapted to their surroundings that they can 
live in no other, and while sheep thrive better if not infested by para- 



19 

sites the latter can not live without sheep. The only exceptions are 
those species which are also parasitic on other animals, as goats and 
cattle. The modifications of organs which have arisen out of the needs 
of parasitism are too mauy to give in detail. The great central fact of 
their lives is that all the parasites have arisen from their kind, and under 
favorable circumstances will reproduce their species, and that they are 
to be treated as the originators of disease and not as the products of 
disease. 

The methods by which sheep become infested diifer with the species. The 
external parasites are usually transmitted by actual contact of sheep 
against sheep. The parasites may, however, be dislodged from their 
former host aud afterwards make their way to another sheep. The first 
is known as mediate, and the second as immediate contact. The dis- 
eases produced by the external parasites are true contagious diseases, 
and should be regarded as such fully as much as any of the more act- 
ively virulent maladies. The transmission with this class of parasites 
is usually an active one; they may, however, be borne from one sheep 
to another by people, cattle, goats, or by locks of wool, when the trans- 
mission would be passive. 

(Estrus ovis, which seems to bridge the gap between the external and 
adult internnl parasites, differs from these groups in being able to act- 
ively infest its host with its young, without an actual contact or inter- 
mediate bearer. Lice, louse-flies, and scab insects may do this in a 
less degree, butnot to that possessed by the (Estrus. The (Estrus larvae 
are never transmitted by contact; they must mature, fall to the ground, 
metamorphose, and emerge as adults before the females can infect sheep. 
The internal parasites are passively conveyed into sheep along with 
the food aud drink consumed, and never actively enter into the trans- 
mission. They may be conveyed either as eggs or very young embryos. 
(Estrus forms the single exception. 

The terms ^^ contagious ^^ and '■'• infectious'''' can be applied to these 
parasites. The former is applicable to those parasites which usually 
transmit themselves to other hosts, the latter to those which are trans- 
mitted to their hosts along with food aud drink. The young of (Estrus 
have no agency in their transmission, and hence infect sheep. 

Parasites are frequently said to invade the hosts which harbor them. 
This is only true of those species which actively undertake migration, 
as scab insects and sheep ticks. A few species invade the organs of 
their hosts after the latter have been infected, thus : The larvse of (Estrus 
crawl from the margins of the nostrils to the sinuses of the head ; the 
lung worms migrate into the lungs; the young embryos of Tcenia mar- 
ginata tnnuel the liver; T. coenur us timuels the brain; (Esophagostoma 
penetrates into the intestinal walls. Those internal parasites which 
undertake active migration in the bodies of their hosts seem to form a 
minor class in the parasitic world, those which lodge in tiie intestine 
and ducts emptying into it forming the majority. 



20 

The ability to select their final lodgment belongs to each species, and 
is the one character on which their own life and that of the species de- 
pends. This is self-evident in the case of external parasites. After 
hosts are once infected by the internal parasites and the young embryos 
are endowed with activity, they either select their proper i)lace while 
being carried along by intestinal fluids, or force their way to it through 
all opposing tissues and against all counter currents of fluids. Those 
embryos which fail to reach these places finally die for want of the nec- 
essary conditions of life. The very ability that is so absolutely neces- 
sary to enable certain of the parasites to reach their chosen organ often 
proves the means of their premature death. Tccnia marginata cysts 
invading the liver become lost in the mass of this organ and perish. 
Multitudes of these parasites injure the capsule of the liver and cause 
the sheep invaded to die long before they have matured sufficiently to 
pass into dogs. The embryos of (Esophagostoma often wander into the 
mesenteries, the retro-peritoneal glands and liver, and perish. 

Parasites escape from their ovine hosts either actively, e. g., the 
young and adults of the louse-flies, lice, mites, and the larvte of (Estrus, 
or passively as eggs or young embryos, the young embryos of the 
Strongylus Jilaria and Ta'nia expansa^ the comi)letely segmented eggs of 
the Strongylus contortuSj and as eggs incompletely segmented. In 
the latter case they are rejected with the excreta of the lungs or intes- 
tines. A very few (the cystic tape-worms) escape only after the death of 
their host by the intervention of some carnivorous animal which swal- 
lows them with its food and liberates them from their imprisonment by 
the processes of digestion. The death of the host is usually caused by 
the carnivora in search of their food. The continuance of the parasites' 
life into the adult stages depends, therefore, on the destruction of their 
host. This fact is contrary to the usual rule of parasitism, which de- 
mands that the host continues to live in order that the parasite may 
live and reproduce its species. 

The length of time and the stage of development at which parasites 
infest their host varies considerably. Lambs have no parasites at birth. 
Within a month or two after, they become infested by a few individ- 
uals of certain species of round worms, and by external parasites. 
From this time on they may harbor any of the species to which they 
become exposed. It will be noticed that the commencement of infection 
begins when the lambs first nibble grass. The louse-flies, lice, and scab 
insects infest the fleeces and skin from generation to generation. Unless 
it should subsequently be proven that the hair-lungvvorm {/Strong- 
ylus ovis-jnUmonalis), and the stomach round worm {Strongylus contortus), 
may also perpetually infest sheep, they harbor no other species through-, 
out their entire life cycles. (TJsirns oris is parasitical only in its larval 
stage, and consumes months in developing. Because it can not take nour- 
ishment when adult, it is believed to pass a very ei)hemeral adult stage. 
The broad ta|>e-worm develops rapidly and disai)pears, its six-hooked 



21 

embryo apparently spending long seasons of suspended life fanctious 
on tbe ground. The fimbriated tapeworm develops more slowly, con- 
suming the greater portion of the year; its embryos may exist on the 
ground for indefinite periods. The cystic tapeworms pass indefinite 
periods as cysts in sheep, depending on their resistance to the vital 
forces of the organs infested and upon the date of their liberation from 
imprisonment. The life cycle of the liver flukes seems to be completed 
in a few months. The majority of the round worms seem capable of 
withstanding the elements while scattered over the pastures for indefi- 
nite i^eriods, either as ova or partially and completely developed 
embryos. Their cycle of life in sheep is of variable periods, depending 
on the species. (Esophagosfoma, some of whose embryos invade the 
intestinal wall, offers a retarded development lasting through months. 
Other species develop more rapidly. The exact cycle for each species 
has not been determined, but most of them become adult in less than 
six months, some in less time than three. 

The seasonal appearance of each species depends on its life cycle, 
the average temperature and the humidity of the season, and the age 
of the lambs. Spring and fall seem to offer the most outbreaks of dis- 
ease produced by i^arasites. Summer and winter also have their spe- 
cial i^arasitical diseases. Sheei)-ticks, lice, and scab are more prevalent 
in winter when the sheep are closely herded in yards or barns, and when 
they are covered with heavy fleeces. The gad-fly occurs most in June 
and July, but in milder climates it evidently flies the greater part of 
the year. The disease it develops is more prevalent in older sheep, 
yearlings being the youngest that show distinct signs. The broad 
tape- worm infests young lambs early and causes their disease in a very 
few months. March lambs harbor adult worms in May and June, and 
May lambs in August. The fimbriated tape- worm also infests lambs 
early, but does not produce its worst effects until late fall and winter. 
The liver flukes generally appear first in summer and fall. The round 
worms appear in young sheep of three months and upwards. The ma- 
jority of those that produce disease develop it as they grow adult. The 
thread lung-worms {Strong ylus Jilaria) infest lambs, and epidemics due 
to them usually occur from spring to fall. The hair lung-worm, on the 
other hand, develops slowly, and while their presence can be detected 
in the lungs of young lambs it is the lungs of old sheep which show the 
greatest amount of changes due to their invasion. As a rule warm, 
moist seasons are most ftivorable to their development. The climate of 
the United States so varies from North to South and East to West that 
no exact seasonal appearances of the various species can be given. Most 
of the species seem to be present in sheep in greater or less numbers 
the year round. The most important factors in the time of outbreak of 
different diseases seem to be the age of the hosts and the cycle of life 
of the parasite. 



22 

The desfnictireness of each species is dependent on the numbers of 
the invading ])arasites, the organ invaded, the method by which they 
produce disease, and the age of the host. As a rule, most parasites 
produce disease by their numbers, each causing its infinitesimal amount 
of annoyance. The sheep-grub, the broad tape-worms, Dochmius cer- 
mms, and Twnia cocmtrus, are notable exceptions to the rule. But 
few individuals of each of these species are found invading the organs 
of sheep. Their destructiveness depends on the character of the 
annoyance produced and on the organ invaded. A few of nearly all 
species may infest sheep, and seemingly cause no loss, but when any 
of the factors favoring the development of either of the species appears 
they increase innumerably^ and destroy the lives of their hosts. 

Parasites effect injury to the health of sheep in many ways, some of 
which are very evident to all, while others are indefinable and illusive. 
Tiie injuries effected by sheep-scab, by the hair liing-worms, and by 
(Esophagostoma, are easily discovered; but the injuries produced by the 
tape- worms and various species of round worms can not always be de- 
tected in the intestinal walls. In these the method of determining dis- 
ease is not by testing the various organs by the microscope or chemical 
analysis, but by comparing the patient with a healthy animal of the 
same age in action, appearance, weight, etc., and by comparing the 
organs of the patient with an actual or assumed standard. In these 
ways the effects of the subtle diseases produced by the parasites are 
learned and just allowance made for their importance. 

Most parasites mechanically injure tissues. They may either force 
their way through soft tissues as the cysts of Twnia marginata, break 
through the structure of lung tissue as Strongylus ovispidmonaUs, en- 
ter into the intestinal walls as G^sophngostoma^ or lacerate the tender 
mucous membrane as Dochmius cernuus. The adult tape- worms seem 
to irritate the intestines, derange their functions, and cause nervous dis- 
turbances. Dochmius cernuus and perhaps Strongylus contort us seem to 
abstract blood. Other round worms may live on the intestinal contents. 

The ilestruction caused by the different diseases produced by para- 
sites is varied. Scab, lung- worms, flukes, and tape-worms often destroy 
entire flocks. The ravages of other species are less patent. There is 
no doubt, however, that each causes more trouble than has yet been 
assigned to it. The least destructive of the species common to sheep in 
this country seems to be Trichodectes spharocejyhalus, Strongylus Jilicollis, 
S. ventricosus, and Trichocephalus affi,nis. 

No rigid system has been adhered to in the succeeding pages. Nev- 
ertheless, a certain plan of arrangement and treatment will be noticed. 
The highest insects in the zoologic classification precede. These are 
followed by tbe Acarinw or scab mites. The Helminths, embracing 
the riatoda or flat worms, and the Nematoda or round worms, follow in 
turn. A systematic classification of the worms among each other is not 
closely adhered to. It may be noticed further that such an arrange- 



23 

meut permits of a second subsidiary treatment of the subject by group- 
ing the parasites together as regards the organs they infest. The vari- 
ations arising are due in part to the antagonism between the two ar- 
rangements adopted. The above plan was adopted more for conven- 
ience than for its scientific accuracy from any single point of view. 

Concluding, the author desires to give due recognition to all sources, 
from which he has drawn in preparing this work. The chief sources 
of information have been the admirable works of Leuckart, Die Mensch- 
lichen Parasiten, 1868; Eaillet, Elements de Zoologie, 1885; Neumann, 
Traite des Maladies Parasitaires, 1888 ; and A. E. Verrill, Parasites of 
Domestic Animals, Rep, Conn. Board Agriculture, 1870-'71. An en- 
deavor has been made to mention every other source in the text. 

MEASUREMENTS. 

The following tables will assist the reader in reducing the measure- 
ments given in one denomination to those in another. 

Metric system in medicine. 

Grams. 

1 grain or 1 minim equala 0. 06 

15 grains or 15 minims equal 1-00 

1 dram or 1 fluid dram equals 4. 00 

1 ounce or 1 fluid ounce equals 32.00 

The cubic centimeter may be considered identical with the gram for 
water or aqueous solutions. 

Metric system in measurement. 

Inch. 

1 meter equals 39. 37 

1 centimeter equals 3937 or | 

1 millimeter equals 03937 or ^ 

One-hundredth millimeter equals 00039 or ^/oo 

One-thousandth millimeter equals 000039 or js^oTJ 

25 millimeters equal 1 nearly. 

OTHER MEASUREMENTS. 

For approximate measurements a liter (2.113 pints) may be consid- 
ered equivalent to a quart ; a kilogram to 2^ pounds avoirdupois. 

When graduated measures of weight or volume are not at hand, the 
flock-master may use some of the common household utensils. Pint 
and quart bottles, so called, should be tested, as they vary in size. 
The pint contains 16 ounces, or about a pound in weight. The smaller 
bottles are known as 2, 4, 6, 8, and 12 ounce bottles. Vials are quite 
common, those made to contain 1, 2, and 4 drams being most abundant. 
A set of bottles can always be obtained at the drug-store and the size 
marked on them. It is far better, however, to buy a set of graduates 
and other measures, for they are of daily use. Common tumblers con- 



24 

tain from StolO fluid ounces; tea-cups, about 5 fluid ouces; wine-glasses, 
about 2 fluid ounces; tablespoons, half a fluid ounce; dessert spoons, 2 
fluid drams, and teaspoons, 1 fluid dram. 

In spite of the fact that the use of the metric system has been legal- 
ized in the United States, so deeply is the old English system engrafted 
upon the customs of our people that there will necessarily be a con- 
fusion of weights and measures until the use of the former is made 
compulsory. This system is so easy to learn and so easy in practical 
api)lication that it will certainly supersede the other in use, as it has in 
the continental countries of Europe. 



THE SHEEP GADFLY-GRUB IN THE HEAD-NASAL 
CATARRH. 

CESTRUS OVIS, Linn. 
Plates I, II, and III. 

The popular names of this well-known parasite of sheep convey to 
the reader its epitomized life history, long known to veterinarians 
and farmers. Though the life history is a comparatively simple one, 
there are many of its details which are not only unfamiliar to the aver- 
age shepherd, but some of which are unknown even to those who have 
made a special study of these pests. 

The " Sheep Gadfly," the parent of the '' Grub in the Head," is, 
when flying, so small and so quick in its actions that it is very diflQcult 
to see, and still more difficalt to catch. The greater proportion of 
specimens in collections have been raised from the grubs, i, e., the adult 
grubs are collected and placed in a net-covered box, the bottom of which 
is covered by a couple of inches of damp sand. 'In a few minutes they 
bnry themselves in the sand, and in from three to four weeks they re- 
ai>pear as flies. 

C. V. Eiley (Insects Missouri, First Annual Keport, 1868, p. 161) de- 
scribes the fly (Plate I, Fig. 11) as follows: 

lu this stage it looks somethiug like an overgrown house-fly. The ground color of 
the uiiper part of the head and thorax is dull yellow, but they are so covered with 
little round, elevated black spots and atoms (scarcely distinguishable without the 
aid of a magnifier) that thej"^ have a brown appearance. The abdomen consists of 
five rings, is velvety and variegated with dark brown and straw color. On the 
under side it is of the same color, but not variegated in the same way, there being a 
dark spot in the middle of each ring. The feet are browu. The under side of the 
head is puffed out and white. The antenuio are extremely small and spring from two 
jobes which are sunk into a cavity at the anterior and under part of the head. The 
eyes are purplish brown, and three small eyelets are distinctly visible on the top of 
the head. It has no mouth, and can not therefore take any nourishment. The wings 
are transparent and extend beyond the body, and the winglets, which are quite large 
and white, entirely cover the poisers. Its only instinct seems to be the continuation 
of its kind. It is quite lazy, and except when attempting to deposit its young its 
wings are seldom used. 

The male is about as large as the female, but may be known by its 
relatively narrower forehead or space between the eyes^ Catching a 
male at large would be a chance operation, for though they fly to mate 
with the females around the sheep-yards and pastures, they never make 
their presence known by disturbing sheep. 

35 



2G 

Brauer (Monographie der Q^striden, p. 15) records the size of the male 
and female at from 10 to 12""", or about two fifths of an incli ; the width 
between the eyes of the male at 1""" or one-twenty-fifth of an inch, 
and of the female at 2.5""" or one tenth of an inch. The length of the 
wing is 9""", nearly two-fifths of an inch. 

Distribution. — The species occurs all over the world wherever there 
are sheep. It is now too late to learn if it was indigenous in this country, 
but we may believe that it was introduced with the earliest flocks im- 
ported, whether in Mexico or on the Atlantic coast. Brauer, in 18G3, 
stated that it had then lately been introduced into Chili, South America. 

Life history and description of larva. — The interest of the flock-master 
in this species begins when the fly buzzes around the noses of the sheep 
and deposits its young just within the opening of the nostril. Many of 
the older writers on this subject supposed that the fly deposited eggs, 
but Brauer (o. c, p. 151), in agreement with Joly and Dufour, pointed 
out that the genus was one which deposited their young alive. Accord- 
ing to lliley (o. c, p. 164) Samuel P. Boardman, of Lincoln, 111., men- 
tioned the two following independent discoveries: John Brown, "Old 
Ossawattomie," stated in the Ohio Farmer about 1851 that he saw the 
fly drop the jierfectly formed and living grub in the nostrils of sheep. 
About 1861 Dan Kelly, of Du Page County, 111., made the same discov- 
ery, and records the fact in the Prairie Farmer, October 14, 1865. 
Boardman, in 1867, received a letter from Mark Cockrill, of Tennessee, 
who wrote of having made the discovery years previous. Eiley claims 
(o. c, p. 165) that he obtained living maggots from a fly in 1866. 

The young larva, having been deposited within the rim of the sheep's 
nose, soon attaches itself by means of the hooks (Plate I, Fig. 6), and 
begins to make its way upward into the nostrils. The smallest specimens 
collected by the writer are shown in Fig. 7e, natural size, and are not 
much larger than when first deposited ; for the difference between their 
size and that of eggs deposited by flies even smaller than (Estrus oris 
is inconsiderable. These small larvae are in their first stage of growth. 
They are little, white, elongated bodies, less than 2""" long, i. e., about 
one- twelfth of an inch (Figs. 1 and 2). But little of their structure 
can be seen except with a lens. They already show the division of the 
body into eleven segments, two well-defined hooks (Fig. 3a, a), and tvro 
minute terminal breathing pores (Fig. 4a, a). The ventral surfaces 
(Fig. 2) show the little spines which later on are to become strong 
thorns; some of the spines on the sides are relatively bristle-like and 
longer in proportion than they are later on. In their second stage of 
growth (Fig. 7c, c) all the characters are well defined. The skin is 
white and so translucent that the digestive organs, the respiratory ap- 
paratus, and the fine filiform nerves and their gangiia can be readily 
made out ; the spines on the abdomen, the hooks, and the stigmata are 
all more pronounced. In the third stage — that of the mature larva 



27 

ready to undergo its change into a fly (Fig. 7a, a, «, and h) — the charac- 
ters outlined in its first stages have been perfected. It is this stage 
that is commonly seen by those who split open the head of an affected 
sheep. The mature grub averages over 20l"'" in length and 7™'" in 
width, or about three-fourths of an inch long by one-third of an inch 
wide. Its width and length when measured depend much upon its 
state of contraction. Its back is very convex, its abdomen is slightly 
curved but generally flat, its outline is a very elongated oval, with an 
acute head and obtuse posterior end. Half-grown specimens are more 
pointed at the ends and decidedly flatter on the abdomen. From the 
young to the mature larval state there is a decided change of color. 
At first they are white and semi-transparent. They quickly grow 
whiter and soon after take on a tinge of yellow, which, as they mature, 
grows darker and darker. Then, too, on the back of every segment, 
except the first and last, a dark narrow band appears which eventually 
changes from a brown black to a dead black. These bands are rather 
narrower in front, increasing in width backward. On the side of each 
segment below these bauds there is, in mature specimens, a row of dark 
dots. The spines show the same changes, at first white, then tipped with 
brown, and finally changed to black. The spines occur only on the 
abdomen and the closely adjacent edge. They all point backward and 
assist the grub in moving around. 

When the larva is mature it escapes from the nostrils, falls to the 
ground, bores into it for an inch or two, and, according to Eiley (o. 
c, p. 162), contracts during the next forty-eight hours to half its for- 
mer size, becomes smooth and hard and of a black color, tapering as 
in the larva towards the head (Fig. 14). It remains in this state 
three or four weeks, or according to some authorities from fifty to sixty 
days, depending on the weather. When the fly has matured within 
the case it pushes off a little round cap, ascends from the ground through 
the hole left by the larva in its descent, and emerges into day to com- 
plete the cycle of its existence. 

The ofiBce of the fly seems to be merely to reproduce its kind. On ac- 
count of its rudimentary mouth it is unable even to eat. After emerging 
the fly crawls upon some neighboring grass or twig and rests there until 
its wings and body have hardened. During the first part of its life, ac- 
cording to Brauer (o. c, p. 149), it is very sluggish, sitting around in the 
cracks and crevices of the walls of sheep stalls, and is so dull that it 
must be dragged out. When placed on the hand it seldom flies off. 
This dullness vanishes as soon as the fly has reached perfection and the 
right temperature of the air comes. It is then off with a whirr, first 
vertically in the air, and then in the direction of the flocks. 

The effects it produces on sheep and how and where the injury is in- 
flicted may now be stated. 

Bracy Clark, an English veterinarian, describes the effect of the attack 



28 

of the fly in Trausactions Linnean Society, 1797, vol. Ill, p, 315, as 
follows : 

Earh/ symjyioms. — The moment the lly touches this part (the nose) of the sheep, 
they shake their heads aud strike the ground violently with their fore-feet. At the 
same time holding their noses close to the earth they run away, looking about them 
on everj' side, to see if the liy pursues; they also smell to the grass as they go, lest 
one should be lying in wait for them. If they observe one they gallop back, or take 
some other direction. As they can not, like the horses, take refuge in the water, they 
have recourse to a rut, dry dusty road or gravel pits where they crowd together during 
the heat of the day wdth their noses held close to the ground, which renders it diffi- 
cult for the fly conveniently to get at the nostril. 

This description of the action of the sheep when attacked by the fly 
is correct in all but one or two minor points. The sheep's actions when 
running indicate that they are taking every means to shake off and 
dodge a single rather thaTi a number of pursuers. If this quotation 
had also described the sheep huddled under buildings, along fences, 
under rock ledges and shade trees, holding their noses close under their 
fellows, it would have completed a picture familiar to every farmer or 
flock-master. 

The fly only works during the heat of the day, while early in the 
morning and late in the evening the sheep seem to enjoy feeding in 
freedom from its annoyance. 

Pathology.— The young larva deposited in the nostril of the sheep im- 
mediately begins its migrations upward into the dark passages of the 
nose. It progresses by means of its hooks and spines. By firmly fix- 
ing the hooks into the mucous membrane it is enabled to draw up the 
rear part of its body after it, and by pushing upon the spines of the 
abdomen it holds itself in place while it thrusts out its head for a new 
hold. The only appearance of limbs that the larva has is the two rows 
of prominences along each side of the abdomen, as shown in Fig 13. In 
this method of progression lies one cause of irritation to the sheep, viz., 
the hooks sink into the mucous membrane and not only irritate it, but 
cause minute points of hemorrhage which are afterwards indicated by 
very minute black dots scattered over the surface of the nares or in- 
ternal nose. AVhoever has felt the tickling and itching of a fly at tlie 
entrance to, or a foreign body in the nose, can imagine some of the sen- 
sations which induce the sheep to make such attemi^ts to escape its foes. 

As the larva grows in size it finds its way farther into the recesses of 
the nose, and by following the grooved passage (see Plate III, Figs. 1 and 
2) penetrates into the furthest chambers. Fig. i, n, n, shows the young 
larvae wandering over the turbinated bones and in the main passage. 
One of these larva^, advanced in size, is shown at i in Figs. 1 and 2 fol- 
lowing the direction of the channel marked by the straw o, o, which 
emerges into the frontal sinus of the head, Ic. The larvju may also wan- 
der among the windings of the superior turbinated bones p, and finally 
growing to such a size that they can not escape, become entrapped 
there. The same may happen when they wander through the small ori- 



29 

fice, near but below that leading into the frontal sinus, which leads into 
^ thesuperior maxillary sinus. (SeePlatell, «, b.) A bit of straw has been 
inserted into theoritice to show the place of opening. From these jilaces 
the larwTB never emerge, but after maturing undergo calcareous degen- 
eration. Those that arrive in the frontal sinuses seem to thrive, and at 
the proper time are able to retreat through the orifice they first trav- 
ersed and are finally sneezed to the ground. This history and the fig- 
ures illustrating it, which have been drawn from nature, should satisfy 
sheepmen who have thought that because the grubs were in the head 
they must be in the brain. A glance at Plate III, with its three larvae 
in the sinus (there were originally seven in the head which the artist 
figured), will show that there is a bony partition, a, a, a, between the 
brain and the larvte. This is also the case in regard to those small larvae 
which wander among the intricate windings of the upper turbinated 
bone, g. The larvae of the (Estrus, or the grubs, never do and never can 
penetrate into the brain. 

If one may judge from the black dots indicating a i)revious hemor- 
rhage scattered over the mucous membrane, the irritation set up by the 
wandering embryos is very considerable. In the sinuses of heads which 
contain older embryos other changes are to be noticed. They are filled 
with catarrhal matter which has been produced by the irritation of the 
larvaB, and the mucous membrane is greatly thickened. These changes 
may also be observed over the turbinated bones, r/, the greatest changes 
occurring in the superior, the one next the brain. The membrane 
which covers the latter is the one in which the nerves of the sense of 
smell are distributed, and a thickening of the membrane must greatly 
interfere with this sense. This is no small matter, for it is mainly by 
this sense that the sheep separates its food from other herbage. 

In addition to the catarrhal product and thickening of the membrane, 
it has been noticed that the membrane near the base of the turbinated 
bone — near m — is sometimes very dark colored. At this point the 
bone is exceedingly thin and pierced by a number of holes through 
which the olfactory nerves, or nerves of the sense of smell, pass. It is 
not unusual to find the membranes of the brain in the immediate vicin- 
ity blackened by minute dots, indicating a previous inflammation at 
this point. This affection of the membranes is probably caused by an 
extension of the inflammatory process from the nasal cavity. 

When the larv.e become entrapped in the maxillary sinus they ex- 
cite the same catarrhal secretions and thickening of the membranes as 
elsewhere, which finally fill the cavity, the outlet of which is at the top. 
All this irritation is due to the insertion of the claws and scratchiugs 
of the abdominal spines. The larvie live on the material in which they 
move. They seem to obtain plenty of air even in the most crowded 
recesses. They continually cover and uncover the breathing pores 
(Plate I, Fig. 10a), and iu so doing keep them cleaned of all foreign 



30 

material. Bracy Clark says that they make an audible snap in doing 
tills, but the writer has not heard it. 

Late symptoms. — The chief symptom of the disease caused by tliese 
larvae is the catarrhal discharge on the affected side of the nose, which 
gives rise to one of the popular names of the disease, "snot-nose." 
Even this symptom may be absent when but few larvie are present. 

Keumann {Traite des Maladies Parasitaires, 1888, p. 501) accurately 
describes the symptoms of affected sheep as follows : 

Three or four larvie ot Q^strm are frequently fouud in the frontal sinuses of sheep 
which, during life, had never manifested any symptom. It is only when these larvae 
are numerous, and when they are quite well advanced in their development at the 
commencement of spriug-time, that they occasion morbid troubles. The latter begin 
by a discharge, often unilateral, which is at first clear and serous, then thick and 
mucous. Frequently there is sneezing and snorting, accompanied by the expulsion 
of mucus and sometimes of (Estrm larvie. Later the animals turn the head back- 
ward, often shake it, rub the nose against the ground or some other object Avithin 
reach, or with their front feet. As the malady gradually advances the' sheep go with 
lowered head, lifting the feet high as if they were walkiug in water. Sometimes 
they quickly raise the head, carrying the nose to the wind, and then bend it back- 
ward convulsively. From time to time they stagger and are seized with vertigo, but 
do not turn in a circle. In severer cases there is difficulty of bi-eathing, the first res- 
piratory passages beiug obstructed by the larviu or the inflammation of the mucous 
membrane. The eyes are red and watery. The disease may be still further compli- 
cated. The sick lose appetite and rapidly grow poor; they grate their teeth; a 
frothy saliva runs from the mouth ; their eyes roll in the sockets; convulsions arise 
and finally death ensues, sometimes within six or eight days after the appearance of 
the first symptoms. 

But the disease is rarely so fatal; it lasts longer, and the larvie having been suc- 
cessfully cast out, the symptoms generally become more favorable and by degrees 
completely disappear. 

This affection has sometimes been mistaken for "gid, " or "turn-sick," due to Coc- 
nurns cereiralis, whence the name "false gid," or vertigo of CEstrus, which has been 
given to it. Confusion will be avoided by recalling that turning in a circle does not 
take place in the present disease. The latter is nearly always accompanied by nasal 
discharge and snortings, which do not appear in true " gid, " and which, besides, 
show themselves only in young subjects. 

Occurrence. — The larvae of CEstrus ovis may be found in the nasal 
cavities throughout the year, and in nearly all stages of growth. This 
is more especially true of the southern portions of the United States, 
where the winters are mild and short. During the last winter and 
spring, in January and March, larvaj were collected of all sizes. Those 
represented by natural-sized figures (Plate I, Fig. 7), were collected in 
January at an abattoir in Baltimore, Md. Those figured in Plate III 
were collected in May. From the older of these grubs a pair of flies 
were hatched. The presence of very young larvae during the past 
winter is very interesting, and indicates the presence of flies at an un- 
expected season. The usual time for the appearance of the fly is said 
to be during the months of June and July, and the usual period of 
pupation about two months. Two of my experiments showed that the 
time might be three weeks or four weeks exactly. The larvie is said 



to dwell in the nostrils about ten months. This statement has not yet 
been verified. In very young lambs only young larvjB can be found, 
while in yearlings the larvae may be nearly adult, depending on the 
exact age of the iamb and the time it was infected. In yearlings the 
frontal sinuses are small and the grubs easily escape detection. It is 
in two-year-olds and older sheep that one finds the greatest infection. 
In ewes the sinuses are sufiiciently roomy to hold four or five larvue 
without crowding, but wethers, which have small horns, or bucks which 
have very large frontal sinuses, can harbor many more. Earely have 
more than six or seven been found. Cases have been reported in other 
countries where far larger numbers, as many as ten to fifteen, were 
found. The largest recorded number seems to be from sixty to eighty. 
The relatively small number discovered, and the comparatively large 
size of the young when deposited, indicate that each female lays but 
few young. It is very unusual to find more than two or three larvae of 
the same size, especially if they be mature or nearly so. The young 
larvae are sometimes more numerous, six or seven of nearly equal size 
being found together. The presence of all sizes of larvae in the cavi- 
ties is a plain contradiction to the statements made that the fly appears 
only in June and July, for, no matter whether it takes ten months for 
the larvae to grow or not, young and middle sized and mature larvae 
found in the winter time could not all have been laid within the two 
months indicated. 

The more correct statement is that the fly may appear at any time 
when the temperature is not too low, but that they are more abundant 
in early and midsummer. 

Preventive treatment. — Most authorities on this subject recommend 
preventive measures, but practical application of the means and reme- 
dies proposed is necessary to demonstrate their utility. A change of 
pasturage or an avoidance of brush-fields does not seem to be advisa- 
ble unless the sheep are turned into longer grass, for the flies are able' to 
follow the sheep wherever they may go. 

A practical means of prevention consists in smearing the noses with 
a mixture of equal parts of tar and grease, or of tar and fish-oil, or of 
tar and whale-oil. The better way is to apply the preparation directly 
by a brush. Some recommend smearing the salt and grain troughs with 
the mixture, expecting the sheep while feeding to get more or less on 
the nose. This method is not thorough enough. Fish or whale oil 
alone is also recommended. Powers (American Merino, 1887, p. 300) ad- 
vises the following ointment for this purpose : Beeswax, 1 pound ; lin- 
seed-oil, 1 pint 5 carbolic acid, 4 ounces. Melt the wax and oil together, 
adding 2 ounces of common rosin to give body, then, as it is cooling, stir 
in the carbolic acid. This should be rubbed over the face and nose once 
in two or three days during July and August. He also recommends an 
apparatus which may well be used by owners of first-class breeding 
stock, and possibly others who own but few sheep : " A canvas face- 



32 

cover smeared with this mixture (tlie above), or with one of asafuetida 
and tallow, may be hung in such fashion as not to interfere with the 
sight or with grazing and yet protect the lamb against the fly." 

Whatever the preparation nsed it should be periodically repeated 
throughout the season during which the fly is known to trouble the 
sheep, as the nosing of the sheep in the grass, the accumulated dirt, and 
the rain all tend to make the preparation weaker and consequently less 
effective. 

Old authorities recommend plowing furrows iu the pastures, but these 
will be beneficial only while the ground is dry and mellow. Removal 
of the grub immediately after it has been deposited is impractical. All 
grubs seen on the ground should be crushed. Heads of slaughtered 
sheep should be cared for so that mature grubs can not escape to the 
ground. Sheep yards should be periodically cleaned and sprinkled 
with lime. 

Medicinal treatment. — This seems to be hopeless. A study of the life 
history of this parasite, which appears in the south at nearly all 
seasons of the year, and of the anatomy of the recesses into which the 
larva wanders, will convince one of the difficulties to be met with in 
treatment. In the first place, even if a suitable remedy were found, 
the shee])-owner would be compelled to resort to treatment as often as 
he found his sheep troubled, and would have to treat each separately. 
This arises from the fact that irritating fumigations or sneezing pow- 
ders, which pass into the lower part of the nose, would not affect the 
larvae in the sinuses no matter how violent the sneezing which they ex- 
cite. Injections of irritating substances would also fail, excepting pos- 
sibly in the hands of an expert, who, with a syringe and peculiarly bent 
nozzle, could perhaps learn to inject into the nasal sinuses. Even iu 
that case failure would result in a certain proportion of cases, and the 
maxillary sinuses could not be injected, nor would the larvae in the re- 
cesses of the turbinated bones be reached. In addition to all this, 
most remedies which would kill the larvae would injure the delicate 
mucous membranes. For the flockmaster who may wish to try fumi- 
gation or nasal injections, the following recipe for fumigation as given 
by Blacklock is reproduced : 

One person holds the head in a convenient position in front of the operator. The 
latter, having half-filled a pipe with tobacco and kindled it in the usual manner, 
places one or two folds of a handkerchief over the opening of the bowl, then passes 
the stem a good way up the nostril, applies his mouth to the covered bowl, and 
blows vigorously through the handkerchief. When this has continued for a few sec- 
onds the pipe is withdrawn, and the operat'ou repeated on the other nostril. 

Powers (o. c. p. 3()()) advises the following nasal injection, which should 
succeed if any will : 

It is best to procure at the ding store an elastic bulb syringe, price about l|l, with a 
small nozzle (J inches long. Mix turpentine and linseed-oil in eiiual parts. Accustom 
yourself to the action of tlie syringe so that you can gauge it accurately. Let the 
affected sheep be held before you in a natural position, and carefully probe the nos- 



do 

trils with the nozzle uutil you find its bearing and depth (the nozzle will pass up a 
surprising distance— six inches in grown sheeii). Then charge the syringe, intro- 
duce it to the extremity of the nasal cavity, and with a quick pressure inject about 
a teaspoonful of the mixture. Withdraw at once and let the sheep recover some- 
what from the effects of the shot, then treat the other nostril in the same way. » * * 
Keep the mixture well shaken. 

If the nozzle has a properly curved tip the injected mass will be more 
likely to reach the larvte. A trial on the head of a recently dead or 
slaughtered sheep would give the operator more knowledge of the re- 
quirements to be met than any description. Olive oil is preferable to 
linseed. 

Suiyjical treatment. — There remains but one other method of remov- 
ing the parasites, and that is mainly surgical. If the disease is appar- 
ent on but one side (it may be on both), an opening is made into the 
frontal sinus (see Plate II), with a special instrument called a trephine. 
The opening is made on the dotted lines. which connect the middle of 
the eyebrows, and a little nearer the middle line of the head than the 
eye. The operation is a tedious one, requires some skill, and if advisa- 
ble to undertake with a number of shee]), should only be trusted to a 
competent veterinarian. Moreover, the ultimate results are not such 
that the operation could be advised in the majority of cases. Yet, as it 
is the only means that offers any hope for the worst affected, Ziirn's 
directions (Raillet, Maladies Parasitaires, j). 504) for operating are given: 

Cut off the wool which covers the forehead. Trace with colored chalk a transverse 
line uniting the middle of the two superciliary arches (the eyebrows) and divide it 
by another lino passing at the middle of the forehead. The point of choice for tre- 
phining will be in each of the two upper angles thus obtained without engaging the 
lines which limit them. The operation is performed according to the ordinary rules 
of surgery. From the opening made one often sees the larvtv, which are extracted 
by forceps. To kill others benzine moderately diluted with water is injected. The 
Hap of skin is then cleaned, applied to the opening, and sewed to the adjoining skin. 
The whole is then covered with a turpentine coated leather plaster. The patient is 
separated for a few days from other sheep. Sheep bear the operation with the same 
impunity as they do marking the ears or other little operations. 

Trephining may also be resorted to for the large cavities at the base 
of buck's horns, or for the maxillary sinus. The latter is a far more 
difficult operation, and the vicinity of important nerves and blood-ves- 
sels demands that only a skilled veterinarian should undertake it. The 
operation is, after all, only temporary in its effects, for the next larvie 
laid in the nose will crawl into the same sinuses and create the same 
disturbances as those removed. 

Neumann's advice, with which he closes his chapter on this parasite, 
is, perhaps, the soundest to follow, except in the case of breeders of 
valuable sheep : 

At all times, if the number of animals afiected is considerable, the malady should 
be left to follow its course, and those which present the gravest symptoms should be 
sent to the shambles. 

23038 A p 3 



34 



OESTRUS ovis, Liuu. 
Plate I. 

Fig. 1. Larva in the first stage. Dorsal view. 

Fig. 2. Larva in the first stage. Ventral view. 

Fig. 3. Head of larva in the first stage: a, books by wliicb tbe parasite attacbeg 
itself to tbe mucous membrane. 

Fig. 4. Tail of larva in the first stage : a, tbe stigmata or breathing pores. 

Fig. .'j. Hooks of well-developed larva. 

Fig. 6. Hooks of very young larva. 

Fig. 7. Larvte in various stages of growth ; natural size: a, a, a, fully developed 
larvii' in the third stage ; b, three-fourths developed ; c and d, yet younger 
hirvie, possibly in tbe second stage ; <;, the youngest found, and those from 
which figures from 1 to 4 were taken. 

Fig. 8, Cephalic end of full grown larva (Brauer). 

Fig. U. Dorsal view of full grown larva (Brauer), 

Fig. 10. Caudal end of full grown larva (Brauer) : a, stigmata or breathing pores. 

Fig. 11. Adult female fly with line indicating natural length (Brauer). 

Fig. 12. Front view of bead of tbe above (Brauer). 

Fig. 13. Ventral view of full grown larva, showing tbe spines which enable the para- 
site to push itself along tbe smooth, soft mucous membrane. 

Fig. 14. Pupa case dissected to show tbe imago or young fly within (Raillet). 

Fig. 15. Eggs taken from fly (Raillet). 



PLHTE I 







Haines, del. 



CE8TRUS OVIS, 
(The Gad Fly of Sheep. 



36 



CEsTRUS ovis, Linn. 
Plate II. 

Dissection of the head of a sheep to show the cavities into which the gad-fly grubs 
penetrate. The straws indicate the passages from the cavities into the iuside of 
the nose : a, the superior maxillary sinus, in which there is imprisoned the calci- 
fied remains of a fully developed larva ; b, the ridge made by the infra-orbital 
division of the fifth pair of nerves; c, the infra-orbital foramen; d, an opening 
into the nares; e, e, the frontal sinuses with young larva) in them. The dotted 
line /,/, indicates the level at which trepliiuiug, if it is done, should be per- 
formed. Figure reduced to tUree-fourths of natural size. 



'V'*^3^-- 







'•^^jg^' 



38 



CEsTRUS ovis, Linn. 

Plate III. 

Fig. 1. Section of bead of sLeop inado a little to the right of mesial plane: a, a, 
a, a, a, section of bone surrounding h, the brain, and c, the nasial cavity; 
d, the lower jaw bone: e, nostril; /, opening of tear duct; g, g, g, turbi- 
nated bones; h, the posterior opening of the nasal cavity, and near the 
opening of Eustachian tube ; i, placed on the turbinated bone over a grub 
in the groove leading to the frontal sinus; k, the frontal sinus; I, then.asal 
sinus; m, the thin perforated plate of bone called the cribriform plate; v, 
n, n, larva; of (Estrus ascending the nares and wandering about its surface; 
i.'oue ascending to th« sinus; k, opposite three, nearly mature larvie in the 
sinus. Figure reduced to three-fourths of natural size. 

Fig. 2. Outline drawing of the skull surrounding the frontal sinus after removal of 
part of the turbinated bone, lettered as in Fig. 1 ; o, o, straws passed 
through the channels connecting the nares with the sinuses, marking 
the path by which the larva reaches the sinus ; p, cut ends of the removed 
bones. 



THE SHEEP-TICK OR LOUSE-FLY--PHTHIRIASIS. 

MELOPHA.GUS OVINUS, Linil. 
Plate IV. 

One of the best known of all tlie external parasites of sheep is the 
sbeep-tick, MelophaguH ovlnus, Linn. This pest is a very common one in 
the Eastern States, and although it seldom causes any serious damage 
either to the sheep or to the wool, it is at all times an annoyance, and 
occasionally causes decided losses to the flock-master. 

This tick, like a majority of the parasites of the domesticated animals, 
was introduced into this country from Europe. The name " sheep-tick," 
though not a misnomer, as every one knows what a sheep-tick is, is 
misleading. So much do they resemble the true ticks that they are 
often classified together. The most superficial study will, however, 
serve to show their differences. 

Bescri/ption. — The sheep-tick is a wingless fly having but six legs, 
whereas the true ticks are more closely related to spiders, and have 
eight legs in tbeir adult state. The adiilts are less than a quarter of 
an inch long, and have a short, flattened, bristly, leathery body. The 
head is slightly wider than the thorax, into which it is sunk. They 
have very short antennje, which are sunk in sockets in the face; the 
])roboscis is tubular, and is protected externally by two flat, elongated 
bristly pieces, the labrum ; its end is armed with teeth. The thorax 
or limb-bearing portion of their bodies is nearly square when looked at 
from above. It is composed of three pieces, the middle being the one 
seen on the back. Tlie legs are very stout, covered with bristles, and 
each is provided with two strong, sharp claws. The last joint of each 
foot bears a pinniform or feather-like organ whose ofiSce is as yet un- 
determined, but is probably that of coiling around hair for better pre- 
hension. There are no wings. On either side may be seen two small, 
bristle-covered, round spots at points where the wings should be 
attached. At the posterior outer corners of the thorax arc two little 
projections which remind one of balancers. The abdomen, usually 
larger in females than in males, is flattened and bag-like, and is as 
large or larger than the rest of the body, especially after the louse- 
fly has eaten, when the red blood sucked from its host may be seen 
through its skin. Its skin is tough, unsegmented, semi- translucent, 
and permits the abdominal organs to show through. On each side 
there are seven stigmata or breathing pores. The anus is situated on 

39 



40 

the veutral side and just behind the geuital orifice. The sexes resemble 
each other, but may be separated by their size and by the form of the 
external genital ai)paratus. 

In habit these parasites resemble lice living among the hairs of the 
fleece, whence the name, louse-fly. They seldom remain attached to the 
skin longer than a sufficient time to fill up with blood ; this they suck up 
through the proboscis with which they perforate the skin. They try to 
evade capture by runaiug into the wool, and when caught cling tena- 
ciously. 

Life history. — The family of flies to which this parasite belongs is 
truly wonderful, in that they bring forth their young as puparia. The 
puparia of Meloiihagus are laid as flat, ovoid, chestnut brown, glistening 
seed-like eggs, which are nearly one-third as large as the abdomen of 
the parent, and contain an imperfectly developed larva within theni. 
The eg^ cases or j)upa are marked by two rows of seven dots each on 
one surface, a slight depression, indented by two dots in one end, and a 
slight elevation at the other. The two dots are at the anal end. A 
dissection of one of these, taken from a female, shows the pointed end 
to be connected with a membrane, and to be the end through which the 
larva obtains food. 

Some authorities say that each female produces but one or two of 
these puparia ; others say that they can lay about eight or nine during 
their life-time. They lay one at a time in the wool, A portion of eacli 
puparium will be found to be covered with a dry, dark substance, which 
came from the parent when the jjuparium was laid, was sticky, and glued 
it to the surrounding hairs. This prevents the pupa, which becomes 
hard, dry, and glassy, falling from the wool. The insect emerge, 
with adult characters from the pupfe cases, through an opening in the 
end of the case made by a round lid splitting olf, and wanders into the 
wool. Some of these eggs collected in the course of our investigations 
hatched within four weeks at ordinary temperatures. 

Occurrence. — These ticks, or their young, may be found on the sheep 
at all times of the year, but appear to be most numerous in spring. 
They are particularly noticeable at shearing time on the old sheep after 
they are deprived of their shelter. At this time those that can do so 
take refuge in the longer avooI of the lambs, and prove veritable pests. 
The others perish either from being eaten hy the sheep, carried away in 
the wool, or dropped to the ground. They frequently become attached 
to the clothing and persons of people with whom they come in contact, 
but they prove but a slight source of discomfort, as they are easily 
caught and killed. It is not at all probable that they can exist many 
days apart from the sheep, as they are unfitted by structure for any 
other habitat. Their food consists wholly of the blood which th.oy suck 
from the sheep. They depend also on the sheep for warmth ; in warm 
spring days t\xe,y may be fouiul crawling near the ends of the wool, 
while in the colder days they will always be found either engaged in 



41 

feedinfv or resting at but little (listance from the roots of tlie wool. A 
dozeu or more of these ticks, which were moderately well fed when 
taken from the sheep were, with some wool, placed in a cotton-stoppered 
bottle and kept in a room with a temperature varying between 60° and 
80° Fah. They all died in less than four days. The leanest succumbed 
first, in about two days, while those that were better nourished grad- 
ually grew smaller and thinner, and lived little longer than the third 
day. Others placed in wool over the damp soil of a geranium in a 
flower- pot died within four days. On the other hand, some young ones 
which were hatched out in a bottle were kept for nearly two weeks, or 
until their daily feeding was neglect.ed. To feed them they were placed 
on the back of my hand. By this means 1 could, with a lens, watch 
tbem bore into the skin and see the abdomen slowly enlarge as they 
drew in the blood. They had some difficulty in penetrating the thick 
skin, but usually succeeded by slipping their tube into a hair follicle. 
At first no itching or irritation was felt, except a slight twinge when 
the bills first penetrated the skin ; but little swellings came on a day or 
two later which itched for over a week. The itching was far more iier- 
sistent than with mosquito bites. TUey must in this way cause lambs 
much discomfort. It was at first thought that a fluid could be seen 
running from the parasite to the hand through the bill, but no more was 
thought of it until the elevations began to rise and itch ; then it ap- 
peared certain that the little pests had secreted a poisonous fluid. The 
office of this secreted fluid is probably to assist the flow of blood by 
keeping it from clotting. 

The above experiments show that the jiarasite spends its whole life 
on the sheep. 

Source of contagion. — The fact that this parasite passes its whole life on 
the sheep, and that it produces but few young, are very important con- 
siderations in eflbrts for exterminating the pest and preventing a new 
infection. They indicate that if all are killed the sheep will not again 
be infected except from other sheep. 

Disease. — The injury sustained by sheep from these parasites varies 
according to the number present. It arises from the itching and pain 
inflicted by them when obtaining their food. A few cause but little 
annoyance, and, were it not that these may become the source of future 
multitudes, would be scarcely worth noticing. To lambs the annoy- 
ance is particularly aggravating, as their skin is tender and the number 
of parasites attacking them after shearing is unusually large. In older 
sheep the irritation is the more noticeable towards spring. At this time 
the parasites are more numerous and the animals bite and scratch them- 
selves often er. 

Medical treatment. — The well-known means of ridding the sheep of 
these pests are the tobacco or other mixtures used for scab-dips. The 
best time of the year to dip is at shearing time. Then the older sheep 
can easily be handled and cleansed. The dipping should not be delayed 



42 

long after, for oach additional day is one of torment to tlie lambs. The 
lambs also should be thoroughly dipped. Oue dip is said to be sutlicneiit 
to kill the old parasites. However, a few of the i^upjc may remain in the 
tleece of the Iambs. They should be thoroughly examined two or three 
"weeks after, aud if there are any present they should again be capped. 
All the precautious taken in dipping sheep should be carefully ob- 
served. The shorn wool should be stored where the young ticks which 
may hatch from the pupa cases can not crawl back to the sheep. How- 
ever, they seem to have great difficulty in crawling, aud may not be able 
to go far. An experiment in which some of the pupjc became wet with 
moisture from other ticks in the same bottle demonstrated that they 
would not hatch, and indicates tlwit the sheep bath will very likely kill 
the inclosed larvie. 

In The American Agriculturist, October, 1889, page 490, Mr. Joseph 
Harris advises fall dipping for these pests. This is a good plan if the 
sheep have become infested with ticks after the spring dipping by some 
inadvertence of the master. He advises the use of tobacco, carbolic 
acid, and kerosene emulsion dips. The carbolic acid dip is composed of 
a pouud of soap and a pint of crude carbolic acid to each 50 gallons of 
water. Dissolve the soap in a gallon or more of boiling water, add the 
acid and stir thoroughly. Keep the mixture well thinned, and do not 
let it get into the mouths, nostrils, or eyes of the sheep. Hold each 
sheep in the bath not less than half a minute. 

The formula for kerosene emulsioii is as follows : Churn fresh 
skimmed milk and kerosene together in the proportion of 1 gallon of 
milk to 2 gallons of kerosene, either in a churn or by using a force- 
pump until an emulsion is made. The method of using the force-pump 
is to set it in the vessel containing the mixture and turn the stream 
back into the same vessel. The emulsion will form guickei if boiling 
hot milk is used. For dipping use 1 gallon of the emulsion for each 10 
gallons of water required. Mr. Harris seems to think 20 gallons, with 
a reserve of 10 gallons, sufficient ; but he was evidently thinking of a 
very few sheep. He did not use this emulsion, but a variation made 
with soap, as follows : 

Boil a gallon of water, dissolving a pouud of soap in it; add 2 gal- 
lons kerosene; churn the mixture until it emulsifies, or until all the oil 
is "cut." Use 1 gallon of emulsion to 8 of water. Mr. Harris ad- 
vises dipi)ing twice with an interim of two weeks. 

Fifty gallons ot the dip will suffice for fifty sheep. Seventy would 
probably answer for oue hundred ; but much depends upon the amount 
of waste on account of the liquor being carried off by the fleece. The 
recipe is very easily modified for ranching purposes. 

The emulsion has already been advised for cattle lice in Bulletin No. 5, 
Iowa Agricultural Station, p. 184, May, 1889, aud for cattle ticks in 
Insect Life, Vol. II, No. 1, p. 20, U. S. Department of A griculture, 
July, 1889. Though the efficacy of this remedy against the various 



43 

kinds of insect parasites of domestic animals has yet to be tried in de- 
tail, its importance in this field has already been demonstrated. 

Preventive treatment. — The sheep should not be turned into the old 
pens or pastures until a week after the first dip, by which time it may 
reasonably be supposed that all parasites on the ground have died. To 
avoid the chance of any recently hatched parasites gettiug from the 
ground to sheep in places where the sheep rest, it is best to scrape out 
and cleanse the pens. Animals recently purchased should always be 
dipped before being added to the older tiock. 

By following out a thorough plan of treatment, and by carefully 
guarding the sheep from re-infection, the flockmaster should be able to 
rid his flocks of this pest in a siugle season. 



44 



Fisr. 3. 



Melophagus ovinus, Linn. • 

Tlate IV. 

Fig, 1. Female sheep-tick : la, larva case, each natural size. 

Fig. 2. Male, dorsal view, X8: a, head; h, thorax; c, abdomen; d, limbs; c, oval 
bristle-covered disks, whicli correspond to the points of attachment of wings 
in other llies ; /, rndimei;tary hal teres or poiscrs. 
Male, ventral view, X8: (/, Ji, audi, the three segments oC the thorax; k, the 
external genitals. 

Fig. 4. Female, dorsal view, x8. 

Fig. 5. Larva case, x8: a, cephalic end ; b, two rows each of seven shallow indent- 
ations. 

Fig. 6. Foot: a, the two claws between which hangs b, the pinniform prehensile 
organ; c, the tarsi, whose last joint d supports the preliensile onran • e 
distal end of the tibia. " ' ' 

Fig. G«. Preliensile organ, xOO : a, the segmented mnsenlar portion included within 
the tarsus; ft, the flexible grasping portion. 

Fig. 7. Front view of head: a, the compound eyes; b, the aiitenuic sunk in cnp- 
like cavities; c, the labruni wliich protects the sucking organ. 

P^ig. 8. Tlie sucking apparatus: a, the labrum ; b, the orifice from^which the tube 
protrudes; c, the sucking tube. 

Fig. 9. End of the sucking tube, XP20: a, teeth by which the tube cuts its way 
through tlie skin ; b, rod upon which the teeth are set ; c, tube which has 
lateral orifice iu it. Other details not shown. 

Fig. 10. External genital apparatus of female: a, spine-covered cap which tits over 
b, the genital oriliee above; c, two clusters of spines which seem to be for 
clasping; d, the terminal of the seven pair of stigmata or breathing pores ; 
e, anus. 

Fig. 11. External genital apparatus of male: a, the two lateral of the three eh it- 
inous styles which surround tiie projecting intromittent organ ; b, two 
clusters of spines which seem to be claspers; c, stigmata. 

Fig. 12. Larva ease, xCr. a, case with the broken operculum inside ; fc, cephalic end, 
sliowingline where the operculum splits off and the remains of a ceu^ 
tral orifice through wiiicli nourishment was obtained by the embryo from 
the parent ; c, caudal end showing the two dots corresponding to the two 
terminal stigmata. 

Fig. 13. Larva case with larva, xO: a, ventral view; b, dorsal view. 



PLffiTE IV 




Haines, del. 



MELOPHAGUS OVINUS, 
(The Louse-fly.) 



46 

ter. The markings on the under side of the head and the form of the 
caudal end of male and female seem to differ from others, but these 
difi'ereuces are unessential for the present description. The form that 
most nearly approaches it in general appearance is the Trichodecten 
pilosiis, Giebel, from the horse, but the latter is a relatively larger spe- 
cies. The species is to be found on poorly nourished young sheep in 
places where the wool is scanty. A favorite place is betweeu the legs 
and body, just under the shoulder. Ooarse-wooled sheep are more 
afdicted with them. 

The life history of these pests is very simple. The adults lay their 
eggs on the wool fibers at their base, and a glutinous material sticks 
them there (Plate V, Fig. G). The eggs hatch out in the wool, and the 
young louse emerges by pushing oft' the cap (Figs. 7 and 3). The young 
then grow to be adult. It is most probable that sheep can only get the 
lice from other sheep, as another host of Trichodectes sphwrocephalus is 
yet unknown. The presence of these parasites may easily be learned 
by searching for them or their eggs. Sheep affected manifest their 
presence by scratching themselves with their hind feet or by rubbing 
against stationary objects. 

Disease. — The injury wrouglit b}" this parasite is caused by its life- 
habits. The injury effected by species of Trichodectes is not as de- 
cided as that caused by those of Hwmatopimis, the genus to which the 
true lice belong. The mouth parts of the hitter are so arranged that it 
can live on the blood of its host, and in biting through the skin it 
causes an itching sensation and a wound. The Trichodectes, however, 
are not fitted for penetrating so deeply, and appear to go but little 
deeper than the epithelium. They can probably bite through to the 
young growing tissue, for animals which are severely afflicted with 
these pests have a roughened, scabby skin, which would not be the case 
if the parasite only lived on the hairs and epithelial debris. The pres- 
ence of these parasites on the skin not only gives discomfort to the sheep, 
but causes the skin to thicken, become rough and covered with little 
dry, black scabs, and the wool to become short, dry, gnarly and worth- 
less wherever the pests attack the skin, 



48 



Tkichodectes srH^iaiociiPHALus, N, 

Platk v. 

lu Plato- V, tigs. 1, 2, ;?, (J, ami 7, iiiid in Dale YI, lige. 1. 2, :i, f), 11, 12, K^, and 15 
are equalJy enlarged, and present relalive diliereuces in size and form. Other parts 
are also enlarged .similarly for the sake of comparison. 
Fig. 1. Male, natural length indicated by line. 
Fig. 2. Female, natural length indicated by line: a, head; b, antenna-; c, face; 

(7, cheeks; e, c, dorsal sutures; /,/,/, legs; </, prothorax ; /*, uielathorax; 

i, abdomen; k, dark transverse bauds; 1, line of hairs on each segnu-nt; 

Mt, TO, stigmata or breathing pores; « (tig. 1), male genital orilice; o, female 

genital orifice; p, female claspers. 
Fig. 3. Young specimeu just emerged from shell. 
Fig. 4. Male antenna. 
Fig. 5. Female antenna. 
Fig. 6. Egg soon after being laid : «, cap with peculiar rod-liivc stiiHlure ; ?^, line at 

which the cap is to cleave olf. 
Fig. 7. Egg shell which has lost its embryo and cap: />, h, wool li))ers. 
Fig. 8. Anterior leg: a. coxa; b, trochanter; c, femur; d, tibia; e, tarsi and claws. 
Fig. 9. Posterior leg. 

Fig. 10. Head, ventral side: a, a, antenna; h, 6, ventral continuation of dorsal sut- 
ure; c, c, ventral suture; d, a, mandibles; e, maxilla) showing through 

the chitiuous gular plate; /, the labrum. 
Fig. 11. Tail end of male, dorsal view : «, the last segment; fc, the genital orilice; 

c, chitiuous, hook-like appendages of the genital apparatus. 
Fig. 12. Tail end of female, ventral view: a, the last segment ; b, the genital and 

anal orilice ; c, the claspers. 



PLSTE V 




11 



vv: 




Haines, del. 



TRICHODECTES SPHiEROCEPHALUS, 
(The Sheep Louse.) 




/\-Hoe(i & Co, I.iih . B,-.H.'i 



GOAT LICE. 
Trichodectes limbatus, Gervais. 

riiite VI, Fij,^s. 1-8. 

BescriiHion. — Trichodectes limhatus, Gervais — the Angora louse — re- 
sembles T. climax closely, but differs in specific details. All the brown 
markings on T. limbatus are darker and wider; the head is slightly 
more indented in front ; the dorsal suture (Plate VI, fig. 2 e, e,) is more 
pronounced; the head is wider in proportion to its length. The banded 
margin of the abdomen is wider. The greatest difference lies in the 
disproportion of size between the male and female of T. limbatm, and 
the character of the transverse bands of the abdomen of the male ; the 
abdomen of the male being shorter is relatively wider in proportion to 
its length, and has a quadrangular appearance. The first band is nearly 
straight and one-third shorter than the three succeeding, which are of 
nearly equal length and convex anteriorly, concave posteriorly. The 
fourth and fifth segments bear a second narrow bandnear the posterior 
margin. The egg of this species is larger than that of T. splucrocepk- 
alas or T. climax. 

The marked differences shown between the bands of T. climax and T. 
limbatus was a constant one in all males examined. This feature, in 
connection with the difference in size of the eggs, and the many minor 
differences of form and color, seem to be specific. The males of these 
s[)ecies seem to offer the most tangible characters for separation. When- 
ever other species of this genus are described particular attention to 
the males should, on this account, be given. The females seem to ap- 
l)roach each other more closely. 

Occurrence and disease. — The goat louse is common, und causes more 
trouble to goats than the little red-headed louse does to sheep. When 
present it occurs among the coarse hair along the back and sides of the 
goat. It causes much discomfort and scabbiness of skin. If the ani- 
mals are severely infected they become poor and thin. The Angora 
goat louse caused, in the single flock in which it was seen, not only a 
severe scabby skin disease, but a loss of fleece. The whole back, sides, 
aud head seemed to be completely covered with the parasites, youug 
and old, and nits. 

Treatment. — The disease caused by these parasites is of that class 
which is preventible, and it is inexcusable if it be allowed to continue. 
The history in each case is that of infection from other sheep, goats, or 
Angoras, as the case may be. As the parasites spend their whole lives 
,«>n these animals they may be killed on theui and not be expected to 
23038 A P 1 49 



50 

come again except from other aniiiials of the same kiiul. Yards, where 
any of these animals are kept, shouhl be sprinkled with lime and the 
walls washed vvitli diluted lye, or whitewashed before the animals which 
have been treated are returned. This will ensure safety from any par- 
asites which may have fallen to the ground where the goats have laiu. 
The treatment should be thorough. As these animals are small the 
best method is to immerse them in tobacco water, thus insuring the de- 
struction of every parasite and nit, even those on the nose, by immers- 
ing them while holding the nostrils. If the hair is long on the Angora 
they should by all means be sheared. If it is not desirable to tlip them, 
the selected remedy may be sopped on the skin and wool and thoroughly 
rubbed in so as to wet the skin. 

Medicines may be applied in three forms: in powders, as pyrethrum 
or Persian insect powder, and tobacco dust; iu ointments, as oil or lard, 
with some added ingredient, and iu baths, as the tobacco or arsenical 
dips. Of these the first is the more objectionable and the least vahiable. 
The second is better, but not entirely successful. The third is the one 
which should be used in the majority of cases, as it is the most certain. 

The following recipes are among those iu use, and are recommended 
by various authorities : 

A decoction of stavesacre seeds, 3 ounces to 2 quarts of water, to be 
thoroughly rubbed in. (Neumann.) 

A decoction of stavesacre seeds, 1 ounce to 1 quart of water or vine- 
gar, or half water and half vinegar. (Finlay Dun.) 

In powders, tobacco, pyrethrum, stavesacre aud sabadilla may be 
used, but the last two are not advisable. 

Benzine 1 part, soft soap G parts, water 20 parts, or petroleum (kero- 
sene) 1 part, sweet oil 10 parts. (Neumann.) 

Schlegs' mixture is recommended in Germany for its efficacy and 
liarmlessness when prudently used. Arseuious acid one-half ounce, 
l)otasli one-half ounce, water 3 pints, vinegar 3 pints. (Ziirn.) 

The most eflicacious remedies are the tobacco, or the tobacco and 
sulphur dips, advised for scab. For flocks of large numbers, nearly all 
other recipes are unavailable. 

Mercurial salves should not be used. 

Ziirn advises tobacco 1 part, water 20 parts, or water 20 parts and 
vinegar 10 parts, to be made into a decoction, and vinegar added after 
cooling. Tlie kerosene emulsion may also prove a valuable remedy. It 
should be applied as directed for exterminating sheep-ticks, or by meaus 
of a force-pump and spray-nozzle. 

TEICnODECTES CLIMAX, Nltzsch. 

Plato VI, Figs. 11-18. 

The common goat, Gapra Urcm^ L., is quite coinmouly infested by a 
species of louse which has been identilied by the writer as Trichodcctes 
climaxj Nitzsf'.h, and the Angora goat, Capra hlrcusy var. Angorciisis, by 



51 

one wliicli seems to be Trichoflecfes llnibatus, Gervais, or T. climax, var. 
major, Piaget. The uaiiie applied by Gervais is accepted, for the dififer- 
euces between the two appear to be specitic and not varietal. 

Description. — The characters of Trichodcctcs climax are : Head wider 
thau long, quadrangular, presenting a wide but shallow indentation in 
front, at which the two antennal bands stop; antennte hairy, a little 
longer with the male than the female ; the first joint is larger and 
shorter than the others ; the second longer than the third ; the abdomen 
bears median spots, the width of which diminish as their length in- 
creases. The last segment of the male carries two hairy cushions. 
Head and thorax, reddish-brown ; abdomen, pale yellow ; spots, brown- 
maroon; bands, blackened. Length, female, 1.6"^'" ; male, 1.3'"'". (Neu- 
mann.) 

The female of this species is broader and the male a little shorter thau 
in the corresponding sexes of T. sphwroceplialus. The dorsal sutures of 
the head are much darker and plainer ; the edge of the head and ad- 
domen are margined by a pronounced dark band. The differences 
between the anterior and posterior feet are much more decided. The 
dark bands of the back of the abdomen of the male seem to offer the best 
characteristics, viz : They gradually increase in length to the fourth, 
when they begin to narrow. Beginning next the thorax the first band 
is narrow; the second, third, and fourth are wider; the succeeding are 
narrower ; posterior to the line of hairs on the second to the fifth seg- 
ments are extra narrow bands, which are about equal iu width. The 
egg of this species is shorter and narrower. 



52 



TRICHODECTES LIMBATUS, Gerrais. 
Plate VI. 

Fig. 1. Mule, natural length indicated by line. 

Fig. 3. Female, natural length iudicated by line : a, head ; h, antennie ; c, clypeus ; 
d, cheeks; e, e, dorsal sutures; /,/,/, legs; g, xirothorax ; h, nietathorax ; 
I, abdomen; k, k, dark trausverse bands; I. I, lines of hairs; m, m, breath- 
ing pores; n, male genital orifice; o, female genital orifice; ^>, female 
claspers; q, male genital hooks. 

Fig. :?. Head, vcutral view : a, antenna3 ; h, mandibles. 

Fig. 4. Posterior end of female, ventral view: a, genital and anal orifice; h, claspers. 

Fig. 5. Egg: fl, the cap; ft, the line where it splits oft". 

Fig. 6. Antenna of female. 

Fig. 7. Anterior leg: a, coxa; h, trochanter ; c, femur; d, tibia; c, tarsi and claws. 

Fig. 8. Posterior leg. 

Trichodectes climax, N. 
Figs. 11 to 18. Numbered and lettered for the same parts as Fig. 1-8. 



PLffiTE VI 




Haines, del. 



A. Ri>eri & Co. l.iUi . Ba 



TRICHODECTES LIMBATUS, 
(The Angora Goat Louse.) 



TRICHODECTES CLIMAX, 
(The CommoQ Goat Louse.) 



THE ITCH OR SCAB INSECTS-ACARIASIS-ITCH-SCAB. 
Sarcoptes, Latr. ; PsoROPTES, P. Gerv.; Chorioptes, p. Gerv. 

Of all the diseases caused by external parasites those due to the scab- 
makiug' iusects are of the first importance. The losses due to them are 
very heavy, aud are exceeded by those of no other external parasite, 
and equal those of the most destructive of internal parasites. Owing 
to the means used in preventing flocks from becoming infected, aud to 
the extermination of the pests by the proper use of efficacious remedies, 
these losses are annually becoming reduced. It is to be hoped that in 
the near future, through the exercise of proper sanitary laws, this most 
tractable of all the parasitic diseases may be completely exterminated 
in our country. 

Scab is a disease due to the presence of minute insects which lead a 
parasitic life on the skin of their hosts. Jt is caused by the inflamma- 
tion they excite in penetrating the skin, that they may procure food for 
themselves and young, and suitable conditions under which the eggs 
may be deposited and hatched and the young matured. The disease is 
thought by some to be aggravated by a poisonous fluid secreted by the 
insects, which adds to the intense itching. 

The malady proceeds step by step with the growth, propagation and 
decay of the innumerable insects which result from the acquisition of a 
single fertile female or a few pairs of individuals, and the spread of the 
disease, therefore, coincides with an increase in the numbers of the par- 
asites, while the limitation of the disease follows their extermination. 

There are at least three different species of scab-forming insects, 
parasitic on sheep, and each species is not only specifically different 
from the other, but the disease caused by each is different. This is 
due to the variation in the anatomical structure and habits of life in the 
several species of these pests, which causes them to attack the skin in 
different places and by different methods, and hence gives rise to the 
various symptoms common to each disease. 

These insects are known as Acari, and the tliseases they cause as 
acariasis. The various species parasitic on sheep are Sarcopfes scahiei, 
de Geer, var. ovis; Psoroptes communis, Fiirst, var. ovis; ChoriojHes 
communis, Verheyen, var. ovis. Of these the Sarcoptes causes scab of 
the head ; Psoroptes causes common vscab, and the Chorioptes foot scab. 

The life history of these parasites is in general very similar. They 
attack the external skin of the animals in which they live by biting it. 
Soon after scabs are formed. Under these scabs the insects lay their 

53 



54 

ovoid eggs. After two or three days these eggs hatch, and in fifteen days 
the progeny become adult. Each adult female is estimated to lay about 
tifteeu eggs, two-thirds of which produce females. When hatched the 
young invade new territory and lead the life of their parents. The ex- 
tensioQ of the invading hosts is due to their migration and rapid propa- 
gation. The disease usually siH'eads as a constantly growing patch. 
The infected sheep sometimes scatter the scabs by scratching ; these, 
in turn, become new centers of infection. The multiplication of thii 
invading pests ceases only at the death of the host, or when thoy 
are killed by the use of proper remedies. To illustrate the rapid 
increase of the tH'^arcoptes, Gerlach. a scientist, computed that in three 
mouths a single female would produce 1,500,000 progeny. He esti- 
mated that each adult female laid fifteen eggs, of which ten were 
females, and that the eggs became adults in fifteen days. The result is 
shown in tabular form as follows : 

First <;eiicratiou after 15 days produces. 



Second 






30 


Third 






45 


Fourth 






GO 


Fifth 






75 


Sixth 






90 



Fomales. 


Males. 


10 


\i 


100 


50 


1,000 


500 


10,000 


5, 000 


100, 000 


50, 000 


,000,000 


500, 000 



This table presents a ver^^ moderate estimate of the rate of propaga- 
tion. A microscopic examination of minute particles of scab shows 
them to be teeming with young and old parasites, and would seem to 
confirm the estimate given. As but few of the parasites may be trans- 
ferred to a healthy animal, it is evident that up to the second month 
but little advance in the disease will be noticed, but after that tiuie the 
tenfold increase ev^ery two weeks produces an enormous number of the 
parasites and causes the disease to advance with wonderful rapidity. 

THE HEAD SCAB. 
Sarcoptes scabiei, de Geer, var. ovis. 

Description. — The insects which cause this variety of scab are almost 
invisible to the unaided eye, and are among the smallest of the scab- 
making insects. They are known as iSarcoptes scabiei, de Geer, vai-. 
ovis. They may be recognized by their rounded or somewhat oval 
bodies, their small heads, which are furnished with a biting apparatus, 
and by the adult having four pairs of legs. The young have but three 
pairs of legs. Other anatomical characters, which are different in differ- 
ent species, are present, but for the flockmaster these are unessen- 
tial, as the species can be separated by biological characters which are 
plainer and easily understood. 

Disease. — Flead scab begins on the upper lij), and about the nostrils ; 
more rarely it may show itself for the first time about the eyelids and 



55 

ears. Ill these places there is less hair and grease, affording the pests 
better opportnnities of getting at the skin. From these starting-points 
the scabs spread over the forehead, cheeks, eyelids, and occasionally 
over the space under the jaw. In badly infected sheep the disease may 
sometimes extend to the fore limbs, under the belly, around the joints, 
and especially between the folds of the knees, hocks, and pasterns. 
Sheep with coarse dry wool are more likely to suffer this extended 
invasion than those, with tine, oily, and soft wool. Long wool seems 
to offer a barrier to its progress, for the invasion of parts covered by 
short wool is much more rapid. The demarkatiou between the inv^aded 
parts of the head and the healthy wool-bearing portions is quite abrupt. 
In coarse-wooled breeds the disease may rarely cover the entire body. 
The first indication of the disease is shown by the sheep in rubbing or 
scratching its head. The intensity of the itching is manifested by the 
violence of the sheep's action. The first that can be seen ou an infected 
spot is little elevations with soft centers. These elevations break of 
themselves, or through the rubbing they receive, and from them runs 
a watery fluid that in drying forms little hard buuches which stick to 
the skin and adjacent hairs. These little elevations are made by the 
parasites, which sink themselves into the skin. Here the parasites find 
suitable food, grow and produce their young. These migrate and pene- 
trate into the skin as did their parents. Thus the disease spreads 
slowly as the parasites increase. Finally, as they become more numer- 
ous, they cover the invaded skin with a thin layer of scabs. As the 
disease advances the little scabs not only run together, forming one 
mass, but they become thicker, whitened, and hard. Later they run 
together over the nostrils, lips, face, cheeks, forehead, eyes and ears, 
and form a dry, hard, thick, scabby mass. By repeated rubbings this 
scab breaks up, and the skin tears, cracks, and bleeds. Later the 
wounds heal and scars are formed. When the scabs cover the eyelids 
the latter close up and the animal becomes practically blind, being uu- 
able to find its way or to see food. The insects are to be found in the 
moist layer underlying the scabs. 

Source of contagion. — The insects which cause the disease have been 
derived from other sheep with which the recently infected flock may 
hav^e come in contact, or which may have left a few parasites ou some 
brush or stick, or in some trough with which the uninfected flock came 
in contact. The methods of infection are various, but he who under- 
stands that these parasites always come from some where else, and 
always from some infected flock, will soon learn what to do to prevent 
his sheep from becoming infected. The variety of Sarco2)tes parasitic 
on sheep is similar to the variety living on goats, and it has been ex- 
perimentally proven that each variety may be transferred and will live 
on either animal. Some of the varieties living on other animals may 
be transferred to sheep, but they do not thrive. It is not at all prob- 
able, therefore, that sheep are infected from other animals than sheep. 



,56 

Diagnosis. — Head scab can not well be coiifoiiiuled with any other 
variety of scab. The seat of the disease and the presence of the para- 
site, which is scarcely visible to the unaided eye, are sufficient to defi- 
nitely diagnose the raalady. 

Prognosis. — This variety of scab is one of the most amenable to treat- 
ment. Being mostly on the head it is easy to reach with remedies. If 
treated it will prove of little loss to the flock-master, whileif allowed to 
take its course it will continue for a long period, gradually growing- 
worse and rendering the patient more and more unsightly and ill-fa- 
vored. It can cause severe inflammation of the eyes and ears. It can 
hinder the fattening of the animal and cause extensive alterations of 
the tissues of the skin. By affecting the health of the sheep, it will not 
only decrease its weight but materially lessen the amount of wool pro- 
duced. 

Medical treatment. — The worst feature of treating the disease is, that 
treatment for a complete eradication seems to be extreme and out of 
proportion to the end to be attained. Curative treatment always yields 
good results when the application is rational. In the early stages of 
the disease, when the scabs are just formed, simple applications of scab 
dips or ointment are all that are needed; in cases of longer standing it 
will be found necessary to first soften and loosen the scabs with some 
kind of grease ot oil, and then to removethem with some alkaline solution 
or soap. The thin oils (sweet oil) that penetrate are the best. The wool 
adjacent to the scabs should be cut away so as to allow the remedies to 
get at the newly affected portions. 

COMMON SCAB. 
PsoROPTES COMMUNIS, Fiirst., var. ovis. 

Plates VII and VIII. 

Common scab is caused by an insect known as the scab mite or itch 
insect— Psoro/>/es communis, Fiirst., var. ovis. This insect is much larger 
than the Sarcoptes, which causes head scab, being visible to the unaided 
eye. 

Disease. — Of all the diseases of sheep in this country, scab is the most 
feared by the tlockmaster. So insidious is its attack, so rapid its 
course, so destructive its effects, and so difficult is it to exterminate 
that it has justly earned the distinction of being more injurious than 
any other disease caused by external parasites. Scab alone, of the par- 
asitic diseases, has become the subject of legislation in most countries, 
and yet, if proper precautions were taken and a rational treatment fol- 
lowed, this disease could soon be completely eradicated. 

Early symtoms. — Attention to the disease is first attracted by the in- 
fected sheep scratching, biting, and rubbing theniselves. The coats 
of the animals look rough, taggy, and felted. The itching is always 



most violent wben the sheep have been heated by driving or Warming 
in a stable. 

Pathology. — By separating the wool and examining a recently infected 
spot, there can be seen some minute elevations, which differ from the 
surrounding skin in being slightly whiter or yellower, and which have 
been produced by the bites of the pests. The insects themselves can 
be found among the hairs at but little distance from the bites. As time 
l)asses and the insects multiply in numbers these elevations become 
more and more numerous, and closer and closer together, until they 
finally unite over a considerable extent. From the summit of each eleva- 
tion or papule, a watery, serous fluid exudes and accumulates, which 
transforms them into vesicles and pustules, and which in drying cover 
them over with a thin crust. In a few days the whole surface is cov- 
ered with a yellowish, greasy, scaly layer, under which the parasites 
are hidden. As the disease i^roceeds this layer gradually increases in 
thickness by an increase of the serous exudate, and in circumference 
by the extension of inflammation produced by the ever-multiplying par- 
asites which live beneath it, forming scaly crusts. These crusts, in be- 
ing torn out, mainly by the rubbing with which the sheep endeavors to 
allay its intense itching, carry with them the lags of the wool, the loss 
of which is an early symptom of the disease. At a later period the 
crusts are replaced by another set of thicker, firmer, adherent scabs, 
which are still further enlarged by the outward migration of the para- 
sites. As they abandon the center of the scabs these are again replaced 
by a peeling off of the external layers of the skin, which gradually 
heals, while the disease slowly progresses at the outside. The complete 
cure is very slow, and the skin remains thick and folded for a long 
time. In sheared sheep the skin becomes covered by a thick, dry 
crust, like jiarchment, while beneath it remains much swollen. 

Late symptoms and di'if/nosis. — The fleece of scabby sheep presents a 
characteristic rough look. In places the wool is stuck together in 
masses; in others it fails, while in others, which are apparently sound, 
it can be easily plucked oft'. The rubbing and scratching indulged in 
by the sbeep not only tend to tear away the wool but increase the 
irritation of the skin, which may become intensely inflamed and swollen 
and finally eiul in a superficial death of the part. Unlike Sarcoptes^ 
the Psoroptes seeks the longest, thickest wool. It begins its attack along 
the back and extends to the neck, flanks, and rump. The Psoroptes 
are rarely found in the region of the chest and abdomen. They are 
collected in masses on circumscribed surfaces. The scabs they produce 
constantly increase at their edges, aud their number depends on the 
number of places invaded. Owing to the closeness in which sheep con- 
gregate and to their violent scratching the parasites become very gen- 
erally scattered and finally the scabs may run together. 

While few of the parasites are present in the older diseased parts, at 
the edges of the scabs they can be found in swarms. They look like 



58 

little white points. with a browiiisli extremity. If picked up by the 
point of a knife or a sharp stick and placed on the hand they will bo 
seen to move. The six-legged young, the eight legged adults, the 
sexes, couples joined together, and the eggs of this interesting insect 
can easily be identified by the aid of a low-power magnifying glass. 

Prognosis. — Tlie disease is favored in its advance by the seasons in 
which the wool grows longest, and in which the sheep are brought into 
closer contact in sheds. Autumn and winter are the most favorable 
for its spread and rapid advancement. In summer, and especially after 
shearing in spring, the disease makes little, if any, headway until the 
wool has grown to a considerable length, ^ge, temperament, state of 
health, energy, and race of the animals, the length, fineness and abun- 
dance of fleece, and the hygienic surroundings have much influence on 
the advance, progress, and termination of the disease. The young, the 
weak, the closely in-bred, the long coarse-wooled sheep, and those sub- 
jected to bad climate, to unhealthy localities, to ])oorly constructed, illy- 
ventilated sheds, are all more subject to the rapid advances of the 
disease. Ou the other hand, healthy, well-fed, well-housed sheep may 
withstand the ravages of the disease for mouths. 

When left to itself scab causes severe disturbances of the functions 
of the skin, and on account of the intense itching brings on fatigue, 
through loss of rest and sleep. Marasmus and cachexia preceding, 
death may come to weak, iU-nourislied subjects in two or three months. 

The mortality due to scab varies much, depending on the season, gen- 
eral health of the flock, food, shelter, and a variety of other factors. It is 
most disastrous in autumn and winter among sheep poorly fed and housed, 
and of weak constitutions. Many otherdiseases may intervene and carry 
ofif the weakened animals. The death-rate is not the only occasion of 
loss, for whether the shepherd keeps his flocks for mutton or wool he 
will find a loss in either, depending much on the severity of the dis- 
ease. Ewe5 weakoiied by the disease will remain infertile, abort or pro- 
duce but weak and feeble lambs, which will eitiier die or scarcely be 
wortli the rearing. To this loss must be added the decreased value of 
the wool obtained from the first shearing after a recovery from the at- 
tack, due to the mixing of the ends of the old wool with those of the 
new, known as the double ended wool. This mixture lessens the value 
for manufacturing purposes. 

Source of contagion. — Kemembering that common scab is caused by 
insects which the infested flocks are continually spreading broadcast 
by dropping tags of wool by the wayside, by leaving them attached to 
brush, by rubbing posts and fences, it is easy to realize that there are 
many methods of transmitting the malady. Experiments with these 
insects have shown that they can live at a moderate temperature ou a 
piece of scab from ten to twenty days; that they may live after being 
subjected to intense cold; that they die more rapidly when they are in 
contact with animal matter at freezing temperature, and that they die 



59 

soon if tliey remain exposed to alternating high and low temperatures. 
These experiments show that the Psoroptes can live about the sheep 
sheds, yards, corrals and fences during twelve or fifteen days, at least, 
after they have separated from the sheep. 

Although this species of parasite is but a variety of the Psoroptes 
communis^ of which the Psoroptes parasitic on horses is another variety, 
the latter has not yet been made to grow on sheep experimentall}'. It 
is not probable that either of the varieties parasitic on cattle or rabbits 
would thrive on sheep. That is to say, so far as is now known, sheep are 
infected with common scab from other sheep, ond can not acquire it 
from other animals. On the other hand, the ovine variety of Psoroptes 
has not yet been found to growou other species of our domestic animals. 

Differential diagnosis. — Psoroptic, or common scab, is different from 
Sarcoptie or head scab, in that the former chooses to live where the fleece 
is longest, and the latter where there is little or none at all — the one on 
the back and sides, the other on the head and occasionally on the nether 
parts; the one is almost invisible to the naked eye, and the other is 
plainly seen, though small. The itch due to other parasites, such as 
sheep ticks and sheep-lice, can be easily separated, because they are 
large and can be found in the wool. Sheep are sometimes subject to 
an inflammation of the sebaceous glands. In this, however, there will 
be no parasites of any kind found. 

Prognosis. — Scab, as has been said before, is one of the most dreaded 
diseases of sheep. For the flockmaster who has but few sheep, say 
fifty or a hundred, the task of treatment and eradication of the scab 
from the flock is no easy afiair ; but for him who owns from five to 
twenty thousand the difficulties to be met are enormously increased. 
Though the disease may be easily tre'ated as far as a single sheej) is con- 
cerned, still the treatment would only be- palliative and would not as- 
snre the flockmaster that the disease would not break out again. 
Treatment, therefore, of a flock in which scab has appeared must be 
applied to every individual exposed and to the corral and sheep-pens 
in which they have been lodged, and is not only a serious time-consum- 
ing affair, but a most expensive one. 

Treatment. — This is of two kinds — preventive and curative. The 
preventive treatment, is undertaken before, during, and after the 
curative. Indeed, if the flockmaster exercises proper care his flocks 
will never require the curative treatment, for the disease always comes 
from transference of the insect. 

Preventive. — An infected flock should be quarantined so that it 
shall not transmit the disease to other flocks, and should be kept from 
public highways where other flocks may pass, until it can be thoroughly 
cleansed and cured. The sheds, yards, and corrals where they have 
been kept should also be cleansed, so that they may not transmit the 
disease. After treatment begins the sheep should be transferred to a 
temporary uninfected yard, so that the old yard may be thoroughly 



GO 

(iisiufected by carting away the soil to some safe spot, by washing all 
the wood-work as high as a man's head with a solution of boiling lye,* 
and afterwards covering it with a coat of whitewash. All old pelts 
which could harbor the insects should be burned. Every possible se- 
creting place for the insects should be overhauled. After a thorough 
cleansing the yards should be left vacant for three weeks. 

After the dipping the sheep should be driven into fresh, clean yards, 
and not into such as have not been sutticiently cleansed. If possible 
they should be kept from infected pasture ranges for three weeks, by 
which time all parasites which nuiy have dropped from them may be 
considered as dead. Sheep which have been dipped in any of the 
tobacco preparations can be, so it is stated, driven on the ranges im- 
mediately after dipi)ing with impunity, as the tobacco odor keeps the 
insects away. Any sheep which may have died on the range should 
either be buried deeply or burned. In dipping extreme care should be 
taken by all who handle sheep not to transfer the pests from animal to 
animal. 

Medicinal. — There are two methods of treating sheep for scab. The 
one of rubbing j^oisonous ointments and oils into the fleece by the hand 
is the oldest and least used. It is slow, tedious, and unreliable, and 
has been superseded by better methods. 

The other consists in immersing sheep in watery mixtures which will 
kill the parasites. This method being cheaper, quicker, and more 
eft'ective, is the one in general use in this country. The formuhe used 
and the methods of applying them vary in different portions of the coun- 
try according to the needs of the sheep-owner. 

In the East, tubs large enough to hold sufficient of the dip to com- 
pletely immerse the sheep, and liettles or cauldrons of a capacity to 
heat the required amount are used, but in the range country of the 
West, where thousands of sheep are to be treated, especially made dip- 
ping pens and tanks through which the sheep may be driven, and large 
boilers made for the purpose, are used. Each method is adapted to the 
needs of the respective localities. Although some dips are fairly eflect- 
ive when applied to sheep with their Heeces on, the dipping should, as 
a rule, be preceded by shearing. This rule should be violated only on 
account of season. If any of the flock are infected all should be sub- 
jected to treatment, otherwise the disease will be carried along and 
break out from time to time. The shearing should take place in a shed 
where all the wool can be cared for, and either i)oisoned or destroyed, 
or so safely stored that it could by no possibility scatter the insects. 
Any treatment undertaken without being preceded by shearing can at 
best be considered as ]>ailiative. 

The object of the treatment is to kill the parasites and their eggs. 
The parasites are killed by the direct application of a poisonous dip. 
The eggs have a thick shell which often resists the effect of the poison, 

* Use 1 part of p<)ta«li to 200 of water. 



61 

and the young parasite emerges in due time. They are then subjected 
to a second dip some six or ten days afterwards, at wbicli time it is pre- 
sumable that all the eggs have hatched and none of the young have be- 
(iome adult. If the second dip is delayed much longer than twelve or 
fourteen days, some of the newly hatched larvic may have become adult 
and laid eggs, which may in turn hatch larvte, and become new centers 
of infection. 

All dips, to be effective, contain some ingredients which are poisonous 
to the parasite. This poisonous element may also, if used in too con- 
centrated a solution, be iioisonous to the sheep, but this is to be avoided 
by using the dips in the exact proportions of the formula given and 
maintaining these proportions throughout the treatment. In addition 
to the poisonous element, a dip may contain other elements, as water to 
<lissolve and to dilute the poison ; also such a substance as alum or soda 
to combine with tlie poison, as arsenic, to make it more soluble ; or it 
may contain an alkali, as soda or potash, to soften the scabs when ap- 
plied ; or it may contain substances which are empirically added because 
they have been experimeutallj'^ l)roveu of service. 

The chief poisons used in the dip are tobacco, arsenic, and carbolic 
acid. Of these, tobacco is the favorite, because its use has not been 
followed by the fatality that has in times ])ast followed the use of 
arsenic. Carbolic acid is too expensive to be used in large. quantities, 
but is an excellent ingredient when only a few sheep are to be dipjied. 

The addition of tar to these dips is excellent, as the tar water is not 
only good for the wounds but serves an excellent purpose of driving 
away the flies. 

The quantity of dip required for each sheep is variously estimated at 
from 1 quart to 1 gallon. For small numbers of sheep, say fifty or one 
hundred, the larger amount is necessary, but for large flocks, 1 quart 
for shorn and 2 for unshorn sheep may be allowed. It is always best 
to have more of the ingredients on hand than is necessary, so that they 
may not be used up before the dii)ping is finished and thus delay the 
business. To make the dip more effective the solution should be ad- 
ministered quite hot. The most desirable temperature is from 100'=' to 
110° Fah., which is a comfortable one for the sheep, whose internal 
temperature is about 103°. The warmth enables the dip to penetrate 
the oily wool better, makes the parasites livelier, and proves far more 
efficient. 

Instead of treating the scab by one application some authorities ad- 
vise the use of a preliminary dip of alkaline water to soften the scabs, 
or of oil or glycerine well rubbed in for the same purpose. This is to be 
followed in two or three days by a poisonous dip. Nearly all advise 
that the scabs should be rubbed with a stiff brush while the sheep is 
being dipped. 

The Australian or Rutherford dip, which has been very successful in 
the hands of large flockmasters, is as follows : Take of tobacco and 



62 

flowers of sulphur 1 pound each, to every 4 gallous of water to be used. 
The tobacco should be steeped in a portion of the water two or three 
successive times so as to extract all of the juice. The leaves or steins 
may be usedj of the latter three times the weight is required as is 
needed of the former ; a i)ress or wringer is convenient to squeeze out 
all of the liquor Ironi them. The sulphur should be mixed with some 
of the tobacco water and stirred until it is of creamy consistency. 
These ingredients should be added to the required amount of water. 
During the dipping this mixture should ))e constantly stirred and a lit- 
tle fresh water added from time to time to replace that lost by evapora- 
tion. 

Tins dip, to be more effective, should be heated to between 100° and 
110"^ Fah. in summer, and 110° and 120^' Fah. in winter, never being 
allowed to fall under or exceed these limits. The sheep should remain 
immersed in it from sixty to ninety seconds, and the head should bo 
completely immersed at least once. 

When sheep with heavy fleeces are dipped it will be found necessary 
to separate the fleece with the hands, that the fluid may permeate better. 
Eight or ten days after the first dipping the treatment should be re- 
peated. Sometimes a third and more rarely a fourth dipping is neces- 
sary. When the last two are required it is most often due to care- 
lessness in preparation, or a failure in the strength of the first dips. 
Sometimes it may be necessitated by the rain having washed off the 
first solution soon after dipping. 

Australian sulphur and lime dip: Take of flowers of sulphur 100 
pounds, of quicklime 150 pounds, water 100 gallons. Mix and stir 
while boiling for ten minutes, until the mixture assumes a bright red 
color, then add 3 gallons of water. Hold the sheep in the mixture until 
the scabs are thoroughly soaked. Immerse the head at least once. Use 
the dip at 100 to 110° Fah. Dip twice at an interval of two weeks. 

In the American Merino, 1887, Stephen Powers gives an excellent 
description of sheep dipping on a large scale, and the following recipes 
in use in various sections of the United States: 

Texas aud New Mexico: Thiitj' pounds of tobacco, 7 iiouuds of sulpliur, 3 pouuds 
of concentrated lye, dissolved in fOO gallous of water. 

Nevada: sulphur, 10 pounds; lime, 20 pouuds; water, GO gallons. 

California: Sulphur, 4 pounds ; lime, 1 pound ; water, enough to make 4 gallous. 

JCansas: Sulphur, 22 pounds; lime, 7 pounds; water, lUO gallous. 

Sulphur and lime is probably tlie cheapest recipe, but the Huge is apt to injure the 
staple ; still this recipe appears to prevail over all others in the scab-infested 
regions. Probably tobacco and sulphur form the best combination known for the 
treatment of scab. To every hundred gallous of water there should be used 35 pounds 
of good strong tobacco (if stems or other inferior parts are used there should be 
more), and 10 pounds of (lowers of sulphur. This preparation used at a temperature 
of 120° Fah., will kill all acari ticks and lice, and leave the wool in a healthy con- 
dition. To iusure thorough work apply a second tiuio in ten days or two weeks, 



63 

Walz's dip, one of the oldest recipes, is as follows : Take of fresh 
slaked liine 4 parts, carbonate of potash 5 parts, mix and boil in barn- 
yard water; add animal oil 6 parts, tar 3 parts; dilute with barn-yard 
lees 200 parts, water 800 parts. To-day this recii)e is more curious than 
useful ; one of the ingredients is not on the American market, and an- 
other is offensive. Veterinarian Clok, in his Diseases of Sheep, 1861, 
reports this mixture as being too weak for old cases, and recommends 
the following modification: Take of freshly-burned slaked liine 6 
pounds, add potash 6 pounds, and water 10 quarts; boil an hour, stir- 
ring occasionally. Add pine-oil 8 pounds, and tar 2 quarts, stirring the 
mixture thoroughly. Make an infusion of 20 pounds tobacco in 130 
quarts of water; add the lye already made and stir. This quantity suf- 
fices for one hundred sheep. Apply by immersing the sheep, separat- 
ing the wool and breaking the scabs. Repeat in eight or ten days. 

Law's recipe (Farmers' Veterinary Adviser) is a very good one: Take 
of tobacco 10 j)0unds, oil of tar 3 pints, soda ash 20 pounds, soft soap 4 
pounds, water 50 gallons. This quantity suffices for fifty sheep. The 
tobacco should be steeped; afterward the other ingredients should be 
added at 70^ Fah. 

Zundel's dip is available, but Dr. Kaiser [Kulirverfahren hei der Schaf- 
raude, 1883) reports that it is too weak in cases of long standing. It is 
said to leav^e the wool clear and white after using. For every one hun- 
dred sheep take crude carbolic acid 3 pounds, caustic lime 2 pounds, pot- 
ash G pounds, black soai) 6 pounds, and water 70 gallons ; mix and boil. 
Dr. Kaiser has obtained excellent results from a modification of this 
recipe. Take of tobacco 5 kilograms ( 13^ pounds), infuse it in 250 liters 
or 06 gallons water; dissolve in it 3 kilograms (8 pounds) soda, add IJ 
kilograms (4 pounds) freshly burned and slaked lime. Dilute 3 kilo- 
grams (8 pounds) black soap (soft soap will do) with hot tobacco broth 
and add it to the rest; then add li kilograms (4 pounds) crude carbolic 
acid, which contains at least 50 per cent, of the pure acid. Mix. This 
quantity is sufficient for one hundred sheep. 

Gerlach's dips, which are administered at two different times for a 
single treatment, are cheap, but owing to the time and labor to be ex- 
pended in performing an operation twice which in other instances is 
done but once, is much more costly than those which require but one 
application. 

Take of potash 2 parts, burnt lime I part, water 50 parts. Mix. Use 
this dip for softening scabs. Follow it in two or three days by the fol- 
lowing: Make an infusion of tobacco 34 pounds in 66 gallons water, by 
slowly steeping the tobacco in a portion of water and finally adding it 
to the remainder. Kepeat the dip in from six to ten days. 

Roloff's dip, for a mixture sufficient for one hundred sheep, is: Take 
7.5 kilograms (20 pounds) of tobacco, steep it with 250 liters (66 gal- 
lons) water for half an hour, heat it to 30^ 11. (95° Fah.) and add 1 
kilogram (2^ pounds) each of purfj carbpljp ^c'l^\ and of potash. 



64 

A cheaper and fully as effective dip of similar formula is the follow- 
ing: IMix an infusion of 15 pounds tobacco with 1 kilo<;ram (2A pounds) 
carbolic acid and 5 kilograuis (13^ i)ounds) wood tar, pcmr it into 250 
pounds (GO gallons) water at 40^ K. (125c> Fah.), in which 3 pounds 
soda has been dissolved. Use it at a temperature of 80° or 90° Fah., 
and repeat in six or seven days. 

There are three arsenical dips favored by European authorities, the 
last of which might be used while exercising proper care and precau- 
tion. The solution should always be kept as dilute as the formula calls 
for. The sheep should not be allowed to drain on the grass, but should 
be kept up until nearly dry, and the laborers who dip should grease 
their arms with linseed-oil before beginning work. 

Tessier's dip, the oldest, was proposed in 1810. To make a mixture 
for one hundred sheep, take arsenious acid 3 pounds, sulphate of iron 
20 pouutls, and water 190 pounds ; boil. 

Tessier's dip causes a discoloration of the wool, which can be removed 
by washing with soap, but it is on this account more or less objectiona- 
ble, and to overcome this objection C16meut has modified it as follows: 
Arsenious acid, 1 part; sulphate of zinc, 5 parts; water, 100 parts. 
The water is put over the fire, the medicinal substances added, and it is 
allowed to boil for eight or ten minutes. After the temperature has 
fallen to the proper degree it is ready for use. The sheep is entirely 
submerged in the liquid, with the exception of the head, the udder of 
ewes suckling their young having beeu previously covered with some 
fatty substance to prevent the action of the astringent on the skin and 
on the secretion of milk. 

Matthews dip : Take arsenious acid 1 part, alum 10, and water 100 
parts. 

Scheurle and Kehm's dip : Take arsenic 1 part, alum 12, and water 
200 parts. This latter is weaker than the former, and therefore safer. 
Moreover, it is claimed to be as effective. 

The sheep dips that are put upon the market are objectionable for three 
reasons: First, their formulas are not given; second, the preparation 
may be valueless, or if not valueless of insufficient strength ; and third, 
the preparation may cost more than it is actually worth. Should the 
dip be put up by reliable houses, and have their formulas i)riuted on 
the outside of the package, the prepared article might prove better 
compounded and absolutely cheaper than the llockmaster could pre- 
pare it. 

Police sanitation. — It is not sufficient that the flockmaster thoroughly 
cures his flock, disinfects his sheds and quarantines his place. Another 
duty awaits him, and that is a public one. All flock-owners should 
unite and assist the State in improving and carrying out its sanitary 
laws. Nearly all States have laws regarding the suppressing and 
quarantining of sheep infected with scab, but they seem to lack in 
stringency and are therefore inadequate. Laws compelling strict quar- 



65 

antine and public supervision of the treatment, at the expense of the 
owner, even though it is undertaken by the State, are demanded for 
the complete eradication of the disease. With such laws no one could 
long harbor on his premises a disease which constantly threatens the 
tlocks of his neighbors with destruction and their owners with financial 
ruiu. 

FOOT SCAB. 

CiioRioPTES coMMur^is, Verheyen, var. ovis. 

This variety of scab, which is due to Chorioptes communis, Verheyen, 
var. ovis, is of rare occurrence. It has been noticed and studied in Ger- 
many by Ziirn. 

The seat of this disease is in the feet and limbs. The disease pro- 
gresses very slowly from the feet, and little by little invades the upper 
parts of the limbs and adjoining parts. It is not readily communicable 
to other sheep and spreads slowly. 

In the beginning this variety of scab is characterized by the redden- 
ing, followed by an abundant scaling of the skin, and later by yellowish 
white crusts. The animals stamp, scratch, and bite the parts, showing 
an intense itching. As the disease progresses the crusts become thicker; 
cracks may form in the folds of the pastern and the limbs become quite 
unsightly. The parasites swarm beneath the crusts, and when found 
form a certain symptom of the character of the disease. 

Foot-scab is not a serious malady, as it readily yields to treatment 
and is of slow extension. Any of the remedies proposed for the treat- 
ment of common scab may be used with good efl'ect. 
23038 A p<=— 5 



m 



PSOEOPTES COMMUNIS Furst., Viir. OVIS. 

Plate VII. 

Fig. 1. Adult male, dorsal view : a, head ; b b, legs; cc, suckers. 
Fig. 2. Adult nuile, ventral view. 
Fig. 3. Adult female, dorsal view. 
Fig. 4. Adult female, ventral view. 

Note.— Figs 1 to 4, Plato VII, and Figs. 1 to '^, Plate VIII, are equally magniHed. 



PLSTE VII 




.?■- 




Haines, del. 



PSOROPTES COMMUNIS, Var OVIS, 
(The Common Scab-Mite.) 



A.Kcirn&Co, r.il 



68 



PSOROPTES COMMUNIS Furst.. var. OVIS. 

Plate VIII. 

Fig. 1. Young female before moultiug for the last time. 

Fig. 2. Egg drawn from a specimen whicb was inside an adult female. 

Fig. 3. Young six-footed larva. 

Fig. 4. a, open, and h, closed sucker of Psoro^j/es from ears of rabbit; c, the rod which 

connects the membrane on the entl with the muscles which close the 

sucker. 
Fig. 5. Two views of the mandibles. The lateral spurs, a, a, point outward 

(Meguin). 
Fig. 6. Head and anterior limb enlarged; ventral view: a, mandibles; 6, antennae; 

c, maxillaj; d, membrane joining the anteunaj ; e, e, e, joints of the limb; 

/, the claw ; g, the ambulacrum or sucker. 
Fig. 7. Male and female of Psoropta communis var. equi (Megnin). 



PLATE VIII 




Haines, del. 



..Kowti&Co. r.ilh. Bxll 



PSOROPTES COMMUNIS, Var OVIS, 
(The Common Scab-Mite.) 



THE PENTASTOMA. 

LiNGUATULA TyENIOIDES, Rud. 
See Plate XVII, li<;s. 1-6. 

Linguatulatamioides \s also known under the names Linguatula rhi- 
7iaria, Pilger, and Fentastoma ta'nioidcs, Rud. 

In describing- this parasite, Neumann's excellent description in Traite 
dcs Maladies Parasitaires, page 491, has beeu taken as a guide. The 
species is probably present in this country, as iu two instances the larval 
form known as Pentastoma denticulatmu has beeu found. The larviB were 
found by Dr. F. L. Kilborne, of this Bureau, iu a rabbit, some time in 
the summer of 1887, and once by myself iu another rabbit in 1888. 

This curious parasite is classed among the Arachnids, being more 
closely related to the spider and mite family than to any other. The 
order Linguatulidce, to which they beloug, is thus defined : 

Eudoparasitic arachnids with elongate, vermiform, annulate body. Mouth want- 
ing jaws in the adnlt state, and surrounded by two pairs of hooks representing rudi- 
mentary feet. No heart. Respiration cutaneous. In it are two genera: (1) Lingua- 
tula, Frohlich, which has the body depressed with dorsal face rounded and with the 
borders crenulated. The cavity of the body forms diverticula in the lateral parts of 
the rings. ("2) Pentastoma, Rud., which has a cylindrical body and the cavity of the 
body continuous. It is not represented in our domestic animals, unless it be a lar- 
val form found once in the peritoneal cavity of a dog. 

Description. — The species met with in the domesticated animals has 
the following characters : 

Body white, lanceolate, very elongate, worm-like, depressed dorso-ventrally with 
the ventral face nearly plane and the dorsal face convex. Anterior extremity 
rounded, large ; posterior extremity attenuated. Cephalo-thorax short, solidified in 
all its width to the abdomen, from which it is scarcely distinct, and which forms by 
far the larger part of the body. Integument showing about ninety rings, larger in 
their middle •, these make the borders of the body crenulated. Hooks acute, re- 
curved, twice-jointed, the basal joint attenuated in its deep part. These hooks, each 
retractile in a pocket, are moved by muscular bundles which act in opposite direc- 
tions. Mouth sub-quadrangular, rounded at the angles; digestive tube simple, rec- 
tilinear; anus terminal. Male, white: length from 18 to 20'"'"; width, in front, 3'""' ; 
behind, 0.5""'", provided with saccular testicles which fill the body cavity even to the 
anterior fourth. Female, whitish grey, often rendered brown by the eggs along the 
median line where the integument is thin and semi-transparent; length from 8 to 
10'^'" ; width, in front, from 8 to 10""", and behind, 21""'. Eggs ovoid ; length, O.Og""'" ; 
width, 0.07™'". 

Life history. — The female Linguatula tceyiioides lays its eggs iu the 
nasal cavities of the dog. These are scattered on the ground and grass 

69 



70 

where they lie until eaten by some herbivorous animal. The shell is 
theu dissolved from around the embryo, nnd it bores through the walla 
of the stomach or intestine into the mesenteric s'bmd, liver, or lung, 
where it encysts itself. In its first stage of active migration tlie larva 
resembles the Acari (Plate XVII, Fig. 4). It has an ovoid body, flat- 
tened on the ventral face, rounded on the dorsal. Its posterior extrem- 
ity is narrowed and dentate. It is furnished with two pairs of articula- 
ted, two-clawed feet, and at its anterior end by a perforating apparatus 
formed of a median stylet and two recurved hooks. Its length is 
0.13"""; its widtli ().()(>""". 

Having arrived at the mesenteric glands, the liver, or the lungs, as the 
case may be, the embryo loses its feet and is transformed into an im- 
movable pupa (Fig. 5), without segments, hooks, or hairs, measuring 
0.250 to 0,300""" long, and 0.180""" in width. 

It emerges from this cyst trausformed iuto another larva, by .1 aeries of successive 
moults (see Fig. (J). The body is elongate, larger forward, and is divided into eighty 
to ninety rings bordered behind by a series of line spines. The digestive tube is 
large, tlie moiitli is elliptical, and surrounded with four characteristic hooiss and with 
accessory hooks. Tiie larva is agamic, its genital organs being rudimentary and rep- 
resented only by a little granular mass in the posterior part of the body. Towards 
the sixth or seventh month the larva is completely developed, measures (> to H""" long, 
and is iu the stage called LinguatuJa dcniicnJata. 

These larva? having escaped from the cyst, fall iuto the serous cavities and remain 
there for some time. They eventually escape, but the precise method is iinkuowu. 
Next they are seen iu the uasal cavities of dogs. Exceptionally, so it is said, they 
are found in the nasal cavities of sheep aud cattle, iuto which they have waudered. 
These larvtc can acquire their full development only iu the respiratory passages. Ouce 
installed iu the uasal cavities they develop iuto egg-bearing adults. Tlie males wan- 
der and can be found at various points of tiie cavities, but the females are more 
sedentary, and are never fonnd iu the etlnnoidal cavities. After tlie death of the 
host they may travel into the pharynx and larynx. They excejjtionally introduce 
themselves iuto the frontal sinuses. They are generally found at the bottom of the 
nasal chamber. 

As the adult stage is not usually found in sheep, and as its occurrence 
is problematical in this country, the disease it causes will not be con- 
sidered in this volume. 

Disease. — The young state, Linguatnla dentictilata, found in cysts 
within the glands, etc., are said to be particniarly frequent in sheep in 
Enrope. Sheep in which the parasite affects the mesenteric glands are 
generally less fat ; their flesh is paler, and they are apparently predis 
posed to an;emia. These glands show no evidences of the [)arasite at 
first, but later they grow browner, smaller, aud are crossed by galleries 
filled with larvae. These cavities are separate at first, but finally com- 
municate ; the substance of the gland is destroyed aud transformed into 
a brown tumor, in the middle of which are the TAngnatuhv. From these 
the parasites often escape through openings with irregular borders; at 
other times the surface is covered by dark, irregular spots, fibrinous de- 
posits, and false membranes, which indicate a recent departure or a de- 



71 

struction of tlie embryos. At hist the tissue is found thickened, indu- 
rated, and offers here and there tuberculoid grains formed from the old 
nests of Linrjnafniw. These altered glands are destroyed and are of no 
further use in nutrition. The larvne create further troubles in their mi- 
grations, but so little is known about these parasites that little can be 
said. 

There is no treatment. Prevention is also difficult. If it should be 
learned that we have these parasites here in considerable numbers the 
best remedy would be to remove the dogs, which are certainly the cause 
of large numbers being' scattered in Europe. 



IMMATURE TAPE- WORMS-BLADDER-WORMS. 

Plates IX, X, aud XI. 

Besides the adult tape-worms tbuud in the intestines of sheep, there 
have been four otlier species described which infest various portions of 
these animals in their immature stager;. These species are Tamia mar- 
ginata, Batsch. T. coenurus, Kiich., T. echinococcus, v. Siebold, and T. 
tenella, Cobbold. The forms found in sheep were first; described as 
Gysticerci, and have since been known as Gysficercus tenuicollis, Coenurns 
cerehralis, Echinococcus and Cystlcercns ovis, respectively. 

All these species resemble each other in their anatomical structure, 
their growth, and their life history. They differ in minute structure, in 
invading different portions of the sheep, and in the effects they produce 
on the animal. 

Tcvnia marginata is more common in the United States, and T. coenurus 
next. Neither of the other two species have been found in sheep in this 
country. 

TAENIA MARGINATA, BatSCh. 
Plate IX. 

Tcvnia marginata occurs in sheep as a little semi-transparent bladder 
filled with liquid, varying from a very minute size to a bag an inch or 
more in diameter, but usually having a diameter of a half or three- 
quarters of an inch. 

Occurrence. — This taenia, in its cysticcrcal stage, is usually found be- 
tween the layers of the serous membrane which form the omentum, or 
'•caul" of the abdominal cavity. It may be found in the liver, espe- 
cially within a week or two after the infection of the sheep by it. A very 
common place to find it is between the folds of serous membrane which 
suspends the intestine in the pelvic cavity. When one of these little 
fluid-sacs are found it may be cut out, with the surrounding tissue for 
examination. Afterwards great care should be taken in dissecting the 
serous tissue, which forms an outer sac, so that the cysficercus within 
shall not be cut, its contents allowed to escape and its walls to collapse. 

Diiscription of cystic stage. — The smaller bladders are apparently com- 
posed of a semi translucent whitish membrane, at one end of which may 
be seen a whitish thickening. As the bladders grow the walls become 
slightly thicker and the spot at the end becomes much larger and pro- 
jects in the form of a knob, 

72 



73 

When the animal is placed iu a saucer of lukewarm water immedi- 
ately after its removal from the slaughtered sheep and examined, it 
can, by the aid of a low-power lens, be seen to possess considerable 
peristaltic movement. This movement is produced by bundles of 
muscles lying at right angles to each other, which may be seen appear- 
ing as a faint striation on the surface. 

The little knob end of the bag is its essential part, and contains what 
is to develop into the future Utnia. Sometimes the animal will extend 
this knob into a cone, and finally thrust out of its center the very tip 
of the cone. By careful handling this so-called head end may be 
squeezed out by the fingers. The tip, when examined by a magnifying 
glass, can be seen to possess four cup-like spots, with a little glittering 
circlet of hooks between them at the very apes of the cone. 

Life history. — When these cysts have attained their hooks and cups 
in a well developed condition, they are ready for transplanting into 
another animal or host. The cysticercus completes its development in 
about eight weeks. It may live a long time after this, and its cyst 
enlarge, but the modifications it may undergo are unessential. The 
host within which the cysts or cysticerci generally develop is the dog. 
They may, however, also develop in other carnivora, such' as the wolf 
or coyote. 

Their emigration is a i)assive one. They remain encysted where they 
are found until the sheep is slaughtered and the dogs eat the offal, or 
until the sheep is killed by a dog or wolf and its liver is torn from its 
place and devoured, together with any of the cysticerci which may be 
attached. Having gotten into the intestines of the host the parasite 
completes its development, becomes adult, and finally jiroduces young, 
which pass from the host along with the ejecta of the intestines. 

The young at this stage are egg-like. They are very small and 
hardly visible to the naked eye. When viewed with a glass they are 
seen to be a minute, jelly-like mass, furnished with six hooks and sur- 
rounded by at least three membranes. The outer is thin and filled with 
fluid ; the inner two more closely surround the embryo, and confine be- 
tween them an oily material which serves to protect it when exposed to 
the atmosphere. 

After passing to the ground these embryos in some way, possibly by 
adhering to food or by floating in drinking water, make their way into 
the sheep. When they arrive in the abomasum, or fourth stomach, it 
is supposed that the gastric juice digests the membranes surrounding 
the embryos and they then begin their active wandering. At this stage 
they penetrate the walls of the fourth stomach and make their way 
between the walls of serous membranes to the place where they finally 
find lodgment. This active migration must often be converted into a 
passive one after the embryo has made its way through the mucous 
coat of the stomach, for when the embryos have been fed in large num- 
bers to the sheep in the course of the experiments of different iuvesti- 



74 

gators tlielivtM" has been found to be filled with iimltitiules of thein. 
One invostij^ator has Ibiiiul thciii in the minute branchk'ts of the portal 
vein, which conchicts the blood from the stonuich and intestines to the 
liver. Now, in order to ai)pear in the liver and in the portal vein in 
such numbers the embryo must make its way into the little branches or 
capillaries which collect the blood at the stomach, ami then be washed 
by the blood current into the liver. When they become lodged in the 
liver they ai;ain migrate actively and tunnel through the mass of the 
liver in all directions. The little channels are made slowly. They begin 
as a minute point, and become gradually larger as the parasite increases 
in size and changes its j)osition. About the ninth day after the embryos 
have been swallowed some of the parasites nmy be as large as a llax- 
seed; most of them will be smaller. They will then be little oval water- 
bags, with a wliitish thickening at the end. 

Some of the parasites seem to pass the entire length of the intestine 
before they penetrate the walls; but when they reach the rectum they 
I)ass through, and, becoming lodged between the layers of serous mem- 
brane, develop there. This i)robably accounts for the presence of the 
considerable numbers which are found in the i)elvis. 

The destination at which these parasites arrive has its influence on 
their development. When they ha^e migrated to a point between 
serous tissues which may be easily spread ai)art, and offer little resist- 
ance to the growing [)arasite, a certain proi)ortion of them seem to 
thrive and arrive at a stage in which they may continue development 
by the proper exchange of hosts. If this exchange is not effected the 
parasite may remain unharmed for a long tinu^. while awaiting this 
opportunity. Should they die from any cause a slow change in the 
appearance of the i)arnsite is noticed. The fluid it contains becomes 
milky and limy. The serous sat; surrounding it becomes thicker; finally 
such changes have occurred that iu place of a soft sac a round, hard 
sphere of lime covered by a thick membrane may be found. The re- 
mains of the parasite may still be seen by careful dissection between 
the cover and the limy deposit. 

But when, on the other hand, they arrive at the liver they seem to 
have reached a place of destruction ; for if they do not kill the invaded 
host within two weeks, a period long before they could continue their 
life in another host, thesame degenerative processes seem to affect them, 
in their earlier stages, whi(;h destroy the older individuals in other or- 
gans of the body. This seems in part due tothe pressure which the liver 
cells aiid cai)sule exert upon them. These statements seem substanti- 
ated by the presence of either scars or calcareous nodules in the liver 
. and of no large ci/sticerci, except where the loose serous membrane may 
have permitted their growth. 

These parasites have occasionally been observed in other parts of the 
system than those mentioned, as in the lungs, heart, and muscles. 

Dificase. — The harm that Taiiia mar(iin<t(a does in its young stage 
depends much on tlui degree of infe(;tion. In experiments auimalshave 



75 

been killed in from nine to twelve tiays after feeding. In sucli cases 
the sheep usually die of hemorrhage from the liver and peritonitis. This 
is caused by the perforations of the serous covering of the liver due to 
the parasites. These experiments show that the [)arasite is injurious to 
sheep. The presence of a few well-advanced ci/sticerci in nearly all of 
our sheep also shows that though the .parasite may be injurious in its 
young stages, the sheep rarely succumbs to them in their period of inva- 
sion. After a period of about two weeks the sheep seem to have no dis- 
comfort from them. 

Sheej) may be invaded by the twnia at almost any time of the year. 
Tlie winter season, when the embryos which ha\'e been scattered by the 
dogs become fiozen, seems to be less favorable. Jf the dogs have 
access to the sheep-pens even this season will not delay the infection. 
Lambs and yearlings appear to be most subject. Three months' lambs 
are the youngest in which the cysticcrci have been found. Experi- 
ments in attempting to ])roduce the cysts in old sheep by feeding gen- 
erally fail. Young shee[) furnish the best specimens, while in five or 
six year old sheep the cjjstieerci seem to have degenerated into calca- 
reous nodules. 

The adult tivnia live in dogs. Soon after the cyst is swallowed the 
tissue is digested from it, and the large, watery bag, which has prob- 
ably already lost its titiid in the mastication of the lood, disajipears. 
The head remains, and passing from the stomach into the intestine at- 
taches itself by its hooks and cups, which serve as suckers. Here the 
parasite, bathed in the intestinal tluids which nourish it, proceeds with 
its development. In a day or two it lengthens and begins to show 
cross lines, which indicate the points where the division into segments 
is to occur. Later the segments api)ear and the worm gradually ma- 
tures the organs of reproduction in them. After ten or twelve weeks 
have ])assed, the parasite begins to lose its end segments, which have 
fully developed embryo in them, and are ready for the infection of sheep. 

Description. — Tcvnia marginat a, Eatsch, or Taenia cysiicerci temncollis 
Kiich., is the largest of the tamia infesting dogs. It is usually, when 
mature, about a yard long. Large specimens may be stretched, when 
fresh, until they are lii- yards long. The greater nund)er of specimens 
are, when contracted, under a yard long. The width of the worms also 
depends on their degree of contraction, the more contracted specimens 
being the widest. The average of relaxed specimens is about two-fifths 
of an inch. The same specimens, when alive, might contract so much 
as to »p.easure three-fourths of an inch. The width of the worm gradu- 
ally v,idens from its head for four-filths of its length, and then contracts 
slightly to the end. This species is moderately thick, measuring a little 
over a twenty-fifth of an inch where thickest. When first taken its ap- 
pearance is white and opaque, but when kept in water it becomes par- 
tially transparent. It then resembles a whitened, pliable baud of gela- 
tine. At its small end is the so called head, which is separated from the 



76 

body by scarcely any constricted neck. The head is quadrangular, is 
about one-twenty-lifth of an inch in diameter, and has a circlet of from 
thirty two to forty hooks at its apex, and four moderate sized suckers. 
The specimen figured contained twenty-eight. These hooks and suck- 
ers serve to anciior the parasite to the intestinal walls. The neck is 
short, and at a little distance from the head shows the division into seg- 
ments which become plainer and plainer towards the end of the body. 
The segments are at first very short and broad, but gradually lengthen- 
ing become square where the animal is widest when relaxed, and about 
twice as long as broad at the end. The terminal segments measure 
about one-fourth of an inch wide and one-half inch long. There is no ali- 
mentary tract, tiie oflice of absorption of food being tilled by the skin. 
Motion is efiected by muscular bundles situated beneath the skin, which 
give a variety of vermicular movements. A primitive nervous organi- 
zation has been described. The entire length of the worm is traversed 
by two canals connected in each joint by a cross system. This system 
is said to serve as an excretory apparatus. It has been called a vascular 
system. Each adult segment contains a complete hermaphroditic gen- 
erative apparatus. They begin to appear in the lirst third of the animal 
and gradually mature toward the last segment. At about the middle 
the eggs become fertilized and develop until the end. The terminal seg- 
ments when ripe separate and pass away. In tliis way the segments, 
which were once near the head, become central and finally' terminal, 
growing adult, maturing their embryo, and passing away in turn. The 
embryonic, shells are 0.()3G""", about one-seven-hundredths of an inch 
thick. The embryo is six-hooked. These worms mature and liberate 
segments in the dog in about ten or twelve weeks after the cysticercus 
has been swallowed. 

Occnrrcnee. — The marginate tape-worm is found at about the middle 
of the small intestine, therein differing from Twnia serrafa, T. ccenurus, 
and T. ciicumerina, which live nearer the end of the small intestine. 
They may be found in dogs of any age. Shepherd or collies, hounds, 
and slaughter-house dogs are most liable to be infected. City dogs, 
which have but little opportunity of being infected, rarely contain the 
parasite. 

Disease. — The harm that the parasite does the dog seems to be in- 
considerable. Were it not that the cj/sficcrcal stage does harm to sheep, 
it might well pass unnoticed by the tlock master. The ease with which 
one can rid his dogs of the parasite seems to place the destruction of 
the species in his hands. For Tamia marginaia alone the administra- 
tion of an effective ta>nicicle every two months would be sullicient; 
but as T. cfcmirus develops in three or four weeks, it would be best to 
treat for botli at once and dose the dogs more frequentl3\ 

Diagnosis. — Every sheep-owner should proceed to dose his dogs with 
worm medicine, whetlier they are known to have tape-worms or not. 
The diagnosis of tape- worms in dogs is difficult, those having many 
often showing no symptoms. Sometimes they may be suspected from 



77 

the leanness of the animals or from the little white segments they pass. 
Such are the benefits arising from thorough medication that the time 
and expense giv^en is well laid out. 

Medical treatment. — The method of treatment consists in tying the 
dog and withholding its supper, not water, over night. Some admin- 
ister a physic at this time. The special worm medicine chosen should 
be given on the next morning, and followed two hours later by a dose 
of physic. The worms, if the treatment has been effective, should be 
voided inside of twelve or eighteen hours. The dog should be fed 
sparingly for a day or two preceding the operation. The preparatory 
physic may be omitted. The dog may be fed at noon on milk or meat. 
He should not be loosened until the following day. The excreta passed 
should be burned or buried in some safe place. The method of admin- 
istering the medicine is as follows: A man of whom the dog is not 
afraid should place himself in a corner and back the dog between his 
legs. He should then grasp the muzzle gently but firmly in one hand; 
with the other hand should pull out the loose cheek at the corner of the 
mouth. Into the pocket thus formed an assistant can put the medicine, 
a dessert-spoonful at a time. The lips should then be held close, and 
the dog will usually move his tongue sutficiently to swallow the dose. 
Should he refuse, his nostrils may be closed for a second or two until 
he gasps for breath, when the medicine will be swallowed. If any con- 
siderable quantity is to be given the operation should not be hurried, 
and should be persevered in with care and patience. Some dogs will 
eat their medicine mixed with milk or soui^, while others are very fas- 
tidious. 

Areca nut has proven itself the best ttenicide for dogs. The freshly 
ground powder is the best. The rule for measuring the dose is to allow 
two grains of the powder to each pound of the dog's weight. The powder 
is thoroughly stirred with soup or milk. If refused, another dose may 
be prepared by mixing it with butter or molasses until the mass is quite 
soft, and administered by hand. Follow the medicine in two hours by 
a table-spoonful of castor-oil for a motlerate sized dog. The oil can be 
given alone or well shaken and mixed with three times the quantity of 
milk. 

If areca nut is not available, a dose consisting of a tea-spoonful of tur- 
pentine and two table-spoonfuls of castor-oil, thoroughly mixed with a 
coffee-cup full of milk, may be substituted. This dose is one for an 
av^erage-sized farm dog. The final physic is not given in this case. A 
2-ounce dose of castor-oil will bring away portions of the tape-worms, 
and sometimes the heads, without the aid of other worm medicine. 

Finlay Dun recommends the following prescription : Take 20 drops 
of the oil of male-shieldfern, 30 of the oil of turpentine, and 60 of ether. 
Beat them together with one egg and give to the dog in soup. 

Ziirn advises the use of about 4 drams of freshly powdered areca nut 
for a very large sized dog, 2i for a medium sized, and 1 dram for a very 



78 

small (log. Tbe powder is to be rubbed up with butter. Follow in two 
hours b^' a table-spoouful of castor-oil. 

Dr. Hageu advises treatment of all sheep dogs each spring and fall, 
thereby claiming an increased immunity for the sheep from the eysticcrci. 
He recomnieiuKs the lollowing: Take of the oxide of copper SO grains, 
of powdered chalk and Armenian bolus 40 grains each ; of water sufli- 
cient to mix the ingredients into an adherent mass; divide into one 
hnndred pills; administer one three times daily for ten days by crush- 
ing them in a piece of meat or bread and butter. 

In addition toother remedies IIoll prescribes the following: (Each 
dose is for large dogs. For smaller ones proportionately less ought to 
be given.) (1) Extract of male fern and the powder of male-fern, 2 
drams each. {'2) A decoction of -5.] ounces of pomegranate-root bark in 
water, reduced to G fluid ounces, and add 1 dram of extract of male-fern, 
to be given in two doses an hour apart. (3) From one-half to 1 ounce 
kousso formed into pills with honey or molasses, and a little meal. (4) 
From 1.^ to 2i drams of Kamala stirred with honey or water, and given 
in two doses inside of an hour. He advises a preliminary preparation 
by feeding the dogs sparingly lor two or three days previous on salted 
food, and the administration of castor-oil the evening before. The rem- 
edies proposed are to be mixed with some material to make them fairly 
acceptable to the patients. With the excei)tion of kamala, which acts 
as a cathartic, all should be followed in two hours by castor-oil. 

After any treatment the patients should be fed with some liquid diet 
on the tirst day. After this they may receive any wholesome food. 

The necessity of repeating a treatment depends entirely on the 
efficacy of the tirst, and the care exercised in preventing a re-infection. 
If the tieatmeiit has been successful in removing the worms, heads and 
all, of course no further treatment will be required. If only portions 
have been removed, then another dosing is necessary. For t(cnia mar- 
(jinata another treatment need not occur under eight weeks, for the 
tapeworm is harmless as far as sheep are concerned ui) to that period, 
for, as far as is known, the worm will not throw off segments before that 
time. For T. cwnurus the treatment should be repeated in about two 
weeks. 

Frcveniive treatment. — The great resource of the flockmaster lies in 
prevention. In this he has nearly absolute control over the health of 
his sheep, in so far as Twuia mar<i'uiata and T. avnuruH are coucerne<b 
As the dogs can only get these taenia from eating viscera of the sheep, 
all the viscera of slaughtered or dead sheep should be withheld from 
them, and either buried, burned, or rendered. 

Police sanitation. — Sheep-killing dogs should be destroyed. Each 
owner should keep his dogs at home, so that all strange dogs may be 
killed in order to prevent them from harming sheep and scattering the 
ta-nia eggs far and witle over the pastures and in the drinking places. 
Dog laws ought to be made sutticiently stringent and adequate for the 
protection of sheep. 



80 



T^NIA MAKGINATA, Batsch. 

Plate IX. 

Fig. 1. Adult taenia, natural size: a, bead (the constricted part following is the 

neck) ; b, point at which the reproductive organs begin to develop ; c, e, c, 

adult segments either separated or about to separate. 
Fig. 2. Head: a, the crown of twentj^-eight hooks; b, b, the suckers or bothria; c, 

the neck, which is transversely wrinkled, but not segmented. 
Fig. 3. Crown of hooks enlarged : a, a, large hooks; b, b, alternating small hooky. 
Fig. 4. Form of single hook. 
Fig. 5. Bladder or Cysticerais ienuicoUis (taken from the omentum or caul of a sheep), 

which produces the tienia when fed to a dog : a, the head ; b, the bladdery 

portion filled with fluid. 
Fig. 6. Head of Fig. 5, enlarged, shows the opening from which the true head may 

be evaginated. 
Fig. 7. Head of the cystic worm, evaginated, shows the suckers and crown of hooks. 
Fig. 8. Segment from near d Fig. 1 shows the branching uterus which is filled with 

ova. 



PLSTE IX 



wu-MiAiVuLidlutt^ 



T-^ 



1 ^1 



7 '^'^ 






^-a. f ^ f' 



A 



- 4 



ih 







JU,,:,.^^' 



r*^'*S 



1 5 



-^ 



■'^JW^ 



t ^^ 



Creo. Marx, dtl. 



TAENIA MARGINATA, 
(The Margined Tape-Worm of Dogs.) 



82 



TAENIA MARGINATA, Batscb. 
Platk X. 

Fig. 1. Portion of a liver from a lamb wliicb died uine days after feeiliug witb tbo 
embryo of Tccnia marginata, drawn from an aleobolic specimen; natural 
size. Tbe surface is seen covered witb sborfcridyes, wbieb run in all direc- 
tions, and are more numerous toward tbe tbiu edge of tbe liver. 

Fig. 2. Cross-.section taken at a a, in Fig. 1, sbows tbe round cross-sections of tbe 
burrows made by tbe young embryos ; also oblique and longitudinal sec- 
tions of tbem. Tbe lower edge is rougb and terminates in liver substauce, 
not in tbe capsule. 

Fig. '^. Young embryo or cysticerci : a, natural size; b, x6. 

Fig. 4. Embryo in tbe state in wbicb tbey are fed to tbe lamb to produce tbe disease. 
(Leuckart), X550. 



%i iTuCllffl 



Haines, de.l. 




LIVER OF I,AMB INVADEP BY ^()^'^•(V TAKN'IA MARGINATA. 



GID OR STAGGERS. 

TAENIA CUiNUKUS, KlicL. 
Plate XI, Figs. 1 to 4. 

The disease wbicU is popularly known as gid, sturdy, staggers, or 
turusick in sheep, is caused by the i)resence of a i)arasite living in the 
brain. This parasite is closely related to 7\vnia marginata. It lives in 
about the same way, but diiJers from it in detail. It is known as T. 
cccnurus in its adult state, and as Ga-nurus cerebralis in its cystic state — 
the stage in which it infests sheep. 

Method of infection. — Sheep become infected with this dangerous para- 
site while pasturing or drinking where dogs have scattered the eggs in 
their wanderings through the country. In the West the eggs may also 
be scattered by the wolves, coyotes, and foxes, which may harbor the 
adult parasite. 

Life history. — The eggs of Tamia cccnurus, after being taken with the 
food or drink, are hatclied within the stomach of the sheep and make 
their Avay through its walls. Tbey then migrate either actively, by 
forcrng their way through the connective tissues, or passively, <as is 
generally believed to be the case, by getting into the circulatory system, 
and are carried from thence into various portions of the body. Those 
arriving in the spinal canal and cranial cavity seem to thrive and grow, 
while the others, which may have reached the heart, lungs, aud dia- 
phragm, grow for a time and then perish. 

Description of cystic stage. — Having arrived in the brain cavity, the 
young embryo migrates upon the surface of the brain much as the em- 
bryo of Twnia marginata does through the liver substance. Tbe gal- 
leries it makes are sinuous. They begin at a point and slowly increase 
with the growth of the parasite and run in any direction. In from two 
to three months after the first invasion of the brain the cysts have 
grown as large as a hazel-nut, or about a half inch in diameter. When 
examined closely they will be found incased in a thick outer skin, a sac 
made by the membranes ot the brain. Out of these sacs the parasites 
may be loosened, and these resemble the cysts of T. marginata. It 
differs, however, in a very important particular — instead of having a 
single knob attached, tens or hundreds of these knobs may be seen as 
little dots hanging from the inner surface into the fluid of the cavity, 
(see Figs. 3 and 4). Each of these dots can evert itself, or push its head 
out, and will theu be seen by the aid of a glass to be a perfectly de- 

83 



84 

veloped bead, haviug four suckers aud a crown of about tweuty-eiglit 
books. These heads, wheu the cysts are fed to do^s, may develoi> into 
as many individuals. Most of them will j;enerally die, and oidy a few 
of the stron<5er will develop. Instead of tbe single worm which tbe 
embryo of T. manjinafa produces, this i)eculiar species develops many 
from each of its embryos. In this there is a compensation ; for while 
many of tbe T. marginata embryos come to maturity, but one or two of 
tbe cfeiiuri survive, aud thus the opportunities for tbe further perpetu- 
ation of the sjiecies are diminished. 

Duration of development. — Experiments bave shown tbat tbe embryo 
may be found iu tbe brain from two to three weeks after feeding, and 
is then about the size of a mustard seed. Between three and six weeks 
after feeding the worst symptoms of the disease occur. Tbe cwnunis 
becomes developed in from two to three months. After this time it 
continues to grow in size and iu tbe number of beads for six or eight 
months, when it usually causes the destruction of the aflected sheep. 
When the developed cwnurm is fed to a dog it usually produces adult 
taj)e worms within a montb. 

In the migrations of these parasites many are lost and destroyed. Of 
the hundreds of eggs wbicb leave the intestines of dogs few reach tbe 
stomacb of the sheep, and of these still fewer enter the cranium. Of 
tbe few which become adult — one or two in eacb shee[) affected — but 
a small percentage nowadays arrive in tbe dog again. Tbus of the 
thousands of embryos that left tbe dog but a single ccenurm may return. 
But this cwiiiirus, developing again into several tai)e-worms, is the 
source of many new embryos for tbe re-infection of the sheep. 

Disease. — Lambs and yearling sheep seem to be most liable to infection ; 
tbose over two years old seem to possess a degree of immunity. Sheep 
berded by dogs ; those breeds which eat tbe grass close to the ground; 
sheep which drink out of i)onds or brooks iu wbicb tbe dogs bathe ; 
flocks belonging to careless flockmasters, who leave tbe skulls and vis- 
cera of slaughtered and dead sheep strewn through the pastures, are 
more liable than others. In short, any of tbe conditions which help iu 
tbe distribution of tbe i^arasites render sbeep more subject to the 
disease. 

Si/m2>toms and progress. — The symptoms of gid iu sbeep are depend- 
ent upon the stage of invasion and development at wbicb the parasite 
has arrived. Tbe iuvasiou embraces tbe period from tbe time tbat the 
eujbryos bave been swallowe<l to the time that they become i)artially 
developetl in tbe brain. Tbe stage of development embraces the re- 
maining time they pass in tbe brain. The stage of invasion generally 
passes unnoticed. Between the second and third week tbose animals 
worst infected — for but few of those infected show signs of disease in 
this stage — show symptoms of intlatumation of tbe brain and surround- 
ing tissues. It is at thii? period that the little parasites are active in 
progressing through the tissues. Dullness, feebieuess, heat iu the head, 



85 

intense redness of the mucous membrane of tlie eyes, and increased 
jHilse-beat are characteristics of tliis stage. The bead is genera! ly held 
in a peculiar position, either stretched at length, turned backward, in- 
clined to either side, or drooped. The intensity of these symptoms 
depends on the number of inv^ading parasites. Later, spasmodic con- 
vulsions or paralysis may occur. Death may take place in about six 
or eight days after the first symptoms are noticed. The diagnosis at 
this stage is difficult, but depends on finding the parasites and their 
channels on the surface of the brain. The former are at this time tlie 
size of a mustard or flaxseed. A correct diagnosis at this stage will 
influence the future treatment of the flocks. If the sheep liv^e through 
this stage no further symptoms will be noticed for from four to six 
months, when a new set of symptoms will appear. It is said that of all 
infected sheep less than 2 per cent, of those which show the disease in 
the early stage recover. 

The symptoms of the second stage arise from two causes — from the irri- 
tation produced by the little heads thrust out of the mother bladder 
and from the disturbances created by the pressure caused by the in- 
crease in size of the coenurns. 

The actions from which the disease has derived its common name in 
all countries are especially characteristic. The head turns : the animal 
walks in a circle; it staggers, trembles, has convulsions, acts stupid; 
it becomes unable to eat or drink, and finally dies of exhaustion or pa- 
ralysis; The various gaits and peculiar positions assumed by the infected 
animals arise from the particular location of the i)arasite. The length 
of time between the attack and death also depemls on this position, 
some parts of the brain being more vital than others. Death occurs in 
a month or a month and a half after the secondary symptoms appear. 

A diagnosis of the disease in this stage can be determined by an ex- 
amination of an infected animal. Sometimes at this stage the parasite 
softens the wall of the skull by its continued pressure and the spot can 
be felt with the fingers. Gmnuri in the s[)inal canal are more difficult 
to diagnose. They cause the sheen to stagger and walk peculiarly with 
the posterior extremities. Sometimes the disease is manifested by an 
intense itching along the backbone without any apparent reason. Paral- 
ysis of the hind limbs and of the rectum and bladder often result. 

The gid should not be confounded with the disease caused by grubs 
in the nasal cavities, which sometimes produce similar symptoms. The 
false gid produced by the larviv of the Oestrus ovis will cause more symp- 
toms of a catarrh or cold in the head and less of the turning, which is 
so very characteristic of true gid. 

Treatment. — There is no treatment that can be profitably followed for 
sheep thus affected. A veterinarian could in the more advanced cases 
locate the position of the cyst either by inference from the character of 
the symptoms or by feeling the softened sj)ot in the cranium. He 
might, by carefully cntting away or trephining the skull over the point, 



86 

remove the parasite and enable the sheep to recover. The intelligent 
farmer might learn to do this himself, bnt after it is all done the cost 
of doing it will abont equal the value of the sheep saved. The true 
treatment, and that which has saved France and Germany more than 
any medicinal or surgical treatment devised, consists in prevention. 

Prevention lies in the treatment of the sheep and of the dogs. As the 
developed ca'tiurus comes only from the craninum or spinal canal, it is 
very easy to prevent dogs from being infected by taking care that they 
can not get these portions of the carcass either when the sheep are 
slaughtered or after they have died in the pasture oj' sheep-cote. The 
heads should either be rendered, burned, or deeply buried, and not 
thrown into the first convenient corner. 

When the skulls and viscera must be fed to dogs they should be sub- 
jected to a prolonged boiling. The soup so made would be harmless. 
When the lambs are known to have passed through the first stage of 
the disease and are fat enough for sale, at the verj' beginning of the 
secondary symptoms they should be slaughtered and marketed, care 
being taken with the first killed to verify the diagnosis. This will save, 
more than any other proceeding. The treatment and handling of the 
dogs are the same as for Tienia margmata, except that T. coemirus, ac- 
cording to Leuckart, develops in three or four weeks, and has to be 
medicinally attended to oftener, or until the dogs are quite free from it. 

The adult. — Tfvnia ccemirus, the adult tapeworm, which grows from 
the cyst and causes the gid when in the sheep's head, resembles T. mar- 
ginata and also T. serrata, a tape- worm which the dog acquires by eat- 
ing the viscera of rabbits in which the young form is encysted. T. ser- 
rata is about as large and long as T. marginata. T. cccnurus is much 
smaller than either, measuring when mature between 1 and 2 feet,while 
the former measures a yard. It is also a slenderer species. The most 
decided differences lie in the hooks of the head. T. serrata has the 
largest head, the largest hooks, and the largest suckers, the latter 
being a third larger than those of T. marginata. They are from thirty- 
eight to forty-eight in number. The hooks of T. aemirus are between 
twenty-four and thirty-two in number, and the slenderest of the three 
species. The terminal segments also vary, those of T. ca'nurvs being 
the smaller. The total number of joints also differ, T. marginata having 
five hundred and fifty or six hundred; T. serrata, three hundred and 
twenty-five or three hundred and fifty, and T. ea-nurns about two 
hundred. Exact measurements of all these parts as given in text-books 
enable one to definitely determine the species, but the flock-master 
needs most to know that his own and his neighbor's dog harbor tape- 
worms, which are prejudicial to his flocks, and to proceed against them. 

The i^resence of Hydatids {Taenia echinococcus, v. Siebold), (Plate XI, 
Figs. 7, 8, and 9), is, if it occurs at all in this country, very rare. It 
has a life history similar to T. marginata, i>assing from sheep, cattle, 
and pigs to dogs, and from dogs back again. In method of growth it 



87 

differs, forming from a single embryo large masses of cysts, which con- 
tain many individuals capable of becoming adult. Its favorite situa- 
tions in sheep are the liver and lungs. It may occur elsewhere. In 
these places it forms large bladdery masses, whose nature can only be 
definitely determined by the aid of the microscope. As this parasite is 
also dangerous to man the bladders should be handled with care, and 
destroyed. The treatment of dogs is the same as for the other lamia. 
Twnia tenella,, Cobbold (Plate XI, Figs. 5 and G), which causes mut- 
ton measles, is a tape- worm of man, and is supposed to be acquired by 
him while eating mutton through which the cysticerci have scattered. 
The disease has not yet been noticed in this country, and having been 
observed but seldom in Europe, is yet problematical. Mutton af- 
fected would present little white spots as large as flaxseed scattered 
through it. The loin muscles are most ajit to be infected. Neither 
this disease nor hydatids can at present be accounted a disease of sheep 
in this country. 



88 



T^NIA CCENURUS, Kiicb. 

Tlatk XI. 

Fig. 1. Adult, natural size (Raillet). 
Fig. 2. Hooks, enlarged (Raillet). 

Fig. 3. Cyst or Cdnuriis cerehralis, Riul. Tlio. white dots arc tlio tionia beads (Raillet). 
Fig. 4. Ideal sectiou tlirougli two of the dots, showing inverted pouches with heads 
of the tienia developing at the bottom (Raillet). 

Taenia tenella (?), Cobbold. 

Fig. .5. Section of beef, showing imbedded ciislirerci. Illustrates the appearance of 

infected mutton. 
Fig. 6. Enlarged head of cijsticerus oris (T. tenella (?), Cobbold), the sheep measles. 

Reduced from Cobbold. 

Taenia echinococcus, v. Siebold. 

Fig. 7. Adult, natural size indicated by line (Leuckart). 
Fig. K Young stages, taken from broad capsule of cyst (Leuck.art). 
Fig. 9. Liver of pig, invaded by echinococcus (Raillet). To illustrate the appearance 
of invaded liver of sheep. 




Haines, del. 



I HoenX Co. lithacaustic. Baltimore. 



TAENIA COENURUS. 



CYSTICERCUS 0VI8. 



TAENIA ECHINOCOCCUS. 



ADULT TAPE-WORMS. 

Plates XII to XV. 

The flocks of this country are infested by two species of adnlt tape- 
worms, remarkably different in form, size, babits, and distribution. 
Tbey are Twnia fimhriaia, Diesing, and T. eximnsa^ llud. Each are 
named from pretlominant characteristics. 

NeniHiiun states that European sheep harbor more species of adult 
tapeworms than other animals, and enumerates ten species which have 
been described, viz: Twnia expansa, Rud; T. alba,, Kerr; T. Benedeni, 
Moniez; T. aculeata, Kerr; T. ovilla, Rivolta; T. Giardi, Moniez; T. 
F<>////, Moniez; T. ccntripunctata^'RiW) T. globijnmctata^lliv.; T.ovipimc- 
tafn, Riv. 

The majority of these species are apparently new to science, and con- 
sequently unconflrnied. Some seem to be well founded, while others 
nuiy eventually prove to be re-descriptions of other better established 
s])ecies. With the exception of T. expansa,, the writer has as yet found 
no traces of any of them, and it is probable that they do not occur 
here. 

A description of the tapeworms found here, and the diseases they 
cause, follows. 

THE FIMBRIATE TAPE-WORM. 

TAENIA FiMBRiATA, Diesing. 

Plates XII and XIII. 

Tape- worms in Western sheep were noticed by ranchmen in the early 
days of rancliiug', but did not attract the notice of veterinarians until 
1883-'84, when Dr. Faville, of the Colorado State Agricultural College, 
first directed attention to them. (Report Veterinary Dej^artment of 
Colorado State Agricultural College, January, 1885.) An earlier epi- 
zootic, due to tape-worms, had been reported to Mr. Stewart, who, in 
the National Live Stock Journal, for September, 1875, records their pres- 
ence in Missouri sheep, and from specimens at hand determined them 
as Twnia plicatd. As this frr/MV^ does not occur in siieep, but in horses, 
it is quite likely that Mr. Stewart saw T. Jimhriata, 

In a recent letter to the Department of Agriculture, the late Hon. J. 
M. Givens reiterates an opinion formerly ex[)ressed by him in local so- 
cieties of wool-growers, and published by him in Denver (Colo.) papers 

89 



90 

of lS83-'84, that these tapeworms were a cause of the larger part of 
the losses among sheep, and urged the necessity of a closer study of the 
subject, iu order that more might be learned of the parasite, the amount 
of loss it caused, and the means of i>rcventing it. These losses had 
previously beeu attributed to a weed called " loco," which tlie sheep ate. 

In obedience to instructions received from the Commissioner of Agri- 
culture, the writer proceeded to Colorado in August, 1880, ami began a 
study of the various intestinal parasites of sheep. Tlie studies of that 
year were pursued, by invitation, on the ranch of Mrs. Mary L. Givens, 
who, at great inconvenience to herself, did all in her power to aid me. 
In the spring of 1887 1 again visited Colorado Springs and prosecuted 
other experiments, which it was hardly possible to conduct iu the East. 

Early in my investigations the fact was recognized that one taenia^ 
identified as Tccnia Jimbriata^'Dies'mg, was the most abundant; that it 
was scarcely ever absent in sheep examined, and was the probable 
cause of most of the tape-worm disease of Western sheep. As this 
twnia was so constantly present attention was directed to it, and an 
endeavor made to obtain it iu all of its stages, and to learn how and 
where it passed its entire life. Another fact was soon learned, that the 
other species of tape- worm [Tccnia cxpansa), usually abundant in lambs, 
was found so infrequently that it was difficult to find sufficient material 
for study. The methods of study were, first, observation, and, second, 
experimentation. The experiments have, as yet, been productive of 
nothing but negative results. In determining so much of the life his- 
tory as has been learned post-mortem observations have been, the most 
useful. Not only have animals been slaughtered on the ranch for this 
purpose, but advantages offered by inspections of sheep slaughtered at 
the shambles for consumption have been utilized. From these iuspec- 
tions the abundance of the parasite, the first appearance in lambs, the 
ditterent stages iu growth, etc., could be learned, but it soon came to 
be necessary to study the surroundings of the sheep — the corral, the 
watering places, and the range — to learn under what condition the par- 
asite must exist while external to the sheep, i. c, while passing from 
sheep to sheep. 

The effects of the parasite on its host (the sheep) were arrived at 
from studies of the flocks and from observation of individuals at j^ost- 
mortenu. The changes found were noted and careful attention paid to 
the point whether certain changes were due to parasites or another dis- 
ease called " loco." As all of the sheep examined were called " locos," 
it is evident that there was here a source of error. No certain patho- 
gnomonic lesion of" loco " was learned ; as all of the " locos " were in- 
fected with t(vnia\ the separation of characters due to each disease 
was difficult. Indeed, it has seemed to me that all of the symptoms 
due to the parasitic divseasemay be ascribed to " loco." The characters 
of the tape- worm disease are, however, well marked in lambs which 
have never learned to eat this weed exclusively, and thus could be 



91 

studied without regard to ''loco," which, if a disease at all, belongs to 
yearlings and older sheep. 

Experimeuts were undertaken with a view of infecting lambs with the 
parasites, while the lambs were kept from other possible sources of in- 
fection ; but these were fruitless. Other experiments were entered upon 
with a view of removing these parasites by medicinal remedies. None 
of these were effective in removing the parasites from the gall-ducts, 
and were abandoned until more could bo learned of the life history of 
the parasite, when they could again be takeu up with perhaps a better 
prospect of success. 

The total results regarding this taniia, so far obtained, are as follows, 
viz: 

The parasite persists in an -adult stage in the okler sheep throughout 
the year. 

The smallest forms ai)pear in lambs soon after the second montli of 
their age, and may be found in sheep of any age throughout the year, 
excepting, possibly, the winter months. 

It requires at least six mouths, possibly ten, to attain an adult size. 

Theovaorembryosare continually passed from thesheep to the ground 
throughout the year. The life of the embryo from the time it leaves 
one sheep until it is found in another is yet undiscovered. 

When present in considerable numbers in sheep it determines a dis- 
ease which is not only detrimental to the value of the animal, but at 
times causes the death of large numbers. 

No medicinal remedies can be recommended which will assuredly re- 
move the parasite from the host. 

Many measures may be taken which may prove to be effective in two 
ways, first, in preventing sheep from becoming infected ; second, in 
enabling the sheep to better withstand the ravages of the parasite, and 
thus carry it over the critical stage of its existence. 

The lambs and yearlings are the greatest sufferers, and it is to these 
that the most attention must be paid. 

T^t:nia fimbriata, Diesing. 

Synonymy. — Thtjsanosoma nctinioides, Diesinj;, IS'.U. Metl. -Talirb. d. oesterr. Staat. 

Nene Folj^e, VII, 10r.-l]l. Taf. Ill (Fi<,^ inverse, delin.), K}- Syst. Helm. I, 

.'iOl iu iiota. 
Tirniafimhriata, Diosing. Syst. Helm. I, .^)0l. 
T(F.nia fimbriata, Diesing, 1856. Zwanzig Arten v. Cephalocotbylcen, p. 11, 18.56. 

Wien. 
Tamia fimbriata, Eept. Dept. Agric., 4tli audfitli Annual Eopts. of Bureau Animal 

Industry, 1887, 1888, p. 167, Pis. I and II. 

Tcenia fimbriata, Diesing, was first discovered by Natterer, in Brazil, 
iu 1S24, and published by Dr. K. M. Diesing in 1834, as a new genus, 
Thysanosoma (ictinioides. Later, in 185G, Dr. Diesing republished this 
parasite as Tcenia fimbriata. (See Plate XIII.) 



92 

The first specimens foninl were detached segments, and from these 
the first description was made, batterer hxter found more complete 
specimens and u[)on these the species was founded. The specimens 
were found in the intestines of the following species of deer, viz : Cer- 
vns palndomfi, C. rufus, G. simplicornis, C. Nambi, (]. dichotomus. 

A translation of the original Latin description is as follows : 

Arhi/ncJtota-nia', Rostellum none ; mouth unarmed. 

Ta'niajimhriata, Diesing. Tab. V, figs. 9-lo. (Plate XIII is a copy.) 

Head obtuse tetragonal, large with liemisplierical angular botbria; ueck none; 
body anteriorly lanceolate, with very short cuneate segments; posterior margin of 
the upper entire, of the following crenato, of tbe last fimbriate on each side ; the lin- 
ear fimbriae rounded at the apices. Genital apertures — ; length 6'" — 6"; width 
1 — 3'". Mature segments, separate, 1'" long, 2'" wide, with lanceolate fimbria;. 

This description was necessarily imperfect, from thelick of abundant 
material, but is nevertheless sufficient to enable us to identify the pres- 
ent species with it. Fortunately, too, excellent figures enable us to 
clearly understand the fimbriate character of the species. At present 
this is the only species known to possess this character. Thougli char- 
acters founded on form are of doubtful value, until more decide<l differ- 
ences are determined between the fimbriate trvnia of deer and those of 
sheep, this decidedly strong character must serve to keep the two to- 
gether. Besides, there are no strong reasons why the two should be 
separate, for each is of about the same size, a fact which we would 
scarcely expect in the same parasite living in hosts of different genera; 
and each is also found in hosts of similar body temperatures, habits of 
life, and of feeding. That they are found in far-separated localities need 
be no serious objection, for the land connection of ^orth and South 
America would permit of tlie infection of deer of both continents with 
the same species of parasites. 

Tcmia jimhr'mta is lanceolate when contracted, linear when relaxed. 
It is quite thick, the flmbriic on the contracted specimens presenting 
the appearance of plush. The segments can only be distinguished on 
the more relaxed six'cimens. Adult specimens are from 15 to .SO"'" in 
length and about S"-'" in width. Immature specimens range from less 
than 5""" upwards. The greatest width is about 2"" from the free end, 
from which point the segments become' narrower. There are at the free 
end of adult specimens ftom three to four or more segments which are 
of nearly equal width, whicii have lost their contractility and are in the 
process of being shed. The shedding of segments begins in youngest 
specimens and (continues throughout the life of the parasite. 

The head or organ of attacliinent is depressed and tetragonal and 
quite large, sitting on the neck like a pin-head; it is from 1 to 1.5""" 
wide, bookless, and has four very large snckers. The substance of these 
cups forms the greater part of the head. 

Tiie neck or the i)art where segmentntion begins is very .short in con- 
tracted specimens, but can be seen in the relaxed condition. The seg- 



9:j 

nieuts are very short and flat near the head, but concave or cup-like 
toward the free end, each overhippiug the succeediug-, and all appearing 
linear on the surface of the twnia. The terminal relaxed segments are 
cuueate. The borders of segments nearest the head are slightly wavy 
or crenate. They soon become fimbriate even in youngest twnia ; so 
that the smallest specimen found demonstrated the fringed character 
of the species. The fimbriiii may either be contracted when they are 
stout and short, or relaxed when they are flaccid and proportionately 
longer. They are obtusely pointed. Tne segmentation in contracted 
specimens is made out with difficulty. It is indicated by transverse 
stritB. In relaxed specimens it is plainer. 

The sexual organs are symmetrically placed, two sets in each seg- 
ment, each opening in a lateral pore. Each set of organs is composed 
of a male and female portion, or is hermaphroditic. The^^ begin to de- 
velop at some distance from the head and attain maturity towards the 
middle of the t(vnia. 

pjesides being remarkable in the fimbriate character of its segments 
this species is also peculiar in the form of its reproductive apparatus. 
The male portion develops first and occupies the wiiole width of the 
young segments. It consists of sacs connected by tubules with a large 
tube which finally becomes the much convoluted efl'erent tube. 

The ovaries develop later, and are situated at each side of the seg- 
ment. They are not shown in the plate. 

The uteri develop last. Each is made of a series of bags arranged 
side by side in a fringe which extends along the top of the segment 
from side to side. These bags open into a larger tube from which they 
receive the developing embryo. The tul)e connects with the ovaries. 
The embryos develop in the uteri, and probably remain there until the 
segments go to pieces on the ground and thus permit them to be scat- 
tered. They are six-hooked and not essentially different from those of 
other taenia. 

Occurrence. — This t(cnia is found in the duodenum and gall ducts of 
sheep. The former is sometimes found containing from thirty to one 
hundred specimens. More often, however, there are from two to thirty. 
The gall ducts are frequently completely distended by the tccnicc, which 
pack them so tightly that the parasites can not be withdrawn by pull- 
ing without breaking. Occasionally one, or at the most two, may tied 
their way into the pancreatic ducts, which they also distend. They get 
into these ducts when young and distend them as they grow larger. 

A few disjointed segments may be found below the duodenum, but 
no entire individuals. Nearly every sheep of a flock will be infected. 

Distribution. — Twnia Jimhriata, Diesing, the fringed tape-worm, is at 
present the most common parasite of the sheep of our Western plains, 
and causes by far the greatest loss of any intestinal parasite in this 
Qountry. 

As niay be seen by inspection of the tables showing parasites foiincl 



94 

ill (lintorent pout mortem observutious, it has been itleiitified in sheep 
from (Jtali, Colorado, and Nebraska. Mr. Codweis, of Grau.i;er, Colo., 
a former sheep-owner in New Mexico, says that lie has seen them there. 
Mr. Samuel Collins, of Colorado Springs, Colo,, who has slaughtered 
sheep from California, Oregon, Utah, Nebraska, and Colorado, says 
that all sheep Iroin these States have them. Dr. Faville personally 
told me that he has seen tliriu from Oregon sheep and from sheep in 
New Mexico. Mr. Stewart's identitication of Tivnia plicata from Mis- 
souri sheep (National Live Stock Journal, September, 1875) leads me 
to suspect its presence in that State. When to these evidences of 
wide-spread distiibution we add those oilcred by the intermingling of 
Western sheep by parentage and traliic, and by the opportunities for 
infection presented by the nearly unrestricted communication of the 
ranges, we may believe that this distribution is necessarily wide- 
spread. Its distribution at present is from Oregon and Wyoming south- 
ward and from Nebraska and Missouri westward, or, more accurately, 
from the ninety-lifth degree of west longitude westward and froni the 
forty-fifth degree north latitude southward. It coincides with the dis- 
tribution of the sheep in those parts, and more especially with that of 
the descendants of the Mexican or Spanish sheep with which nearly all 
of the larger ranches were originally stocked. The precise limit of its 
Eastern distribution is unknown, but is probably limited to those por- 
tions of Nebraska, Kansas, and Missouri to which Colorado feeders have 
been sent i)rior to selling them to the Chicago niarki^ts. 

There are at present no tacts at hand to show that the parasite exists 
east of the Mississippi River. In two instances a number were found 
in sheep slaughtered in Washington, D. C, but these animals were said 
to have come from Chicago, 111. 

Life history. — All of the life history of this twuia that is at present 
known has been learned from post-mortem dissections and microscopic 
investigation. 

The adults were found in yearlings and older sheep throughout the 
year. No adults have yet been found in lambs less than ten months 
old. The smallest stages of the immature tivnia may be found in all 
young sheep over ten months old. They are usually most abundant 
in lambs, yearlings, and two-year olds. Although a sheei) may be in- 
fected with a number of ticnifv of about the same size, indicating an 
infection covering but little space of time, it is more usual to find the 
parasites of various sizes, indicating a continuous infection. The re- 
tention of food and licpiids for some little time in the rumen and reti- 
culum may account for this in part. These varying sizes continue 
from May until December. Sheep examined in May presented various 
sizes and indicated infection in former months. No other data showing 
infection during winter montlis were obtained. The smallest twnicc 
are found in the duodenum ; those found in the gall ducts are larger. 
Twuia less than 2'"™ long have been found in the duodenum after the 



95 

gall duct bas become completely packed by the parasites. The adult 
worms Lave embryos in their most distant segments, wiiich are ready 
to be set free. These embryos escape from the host with the feces. 
Until they reappear in the duodenum of another sheep, a quarter of 
an inch in length, their history is unknown. 

A twnia iuf eating a lamb two months old, the youngest stage noticed, 
is about a half inch long ; as the season advances it is joined by others, 
and these increase in size. Four or live months afterward it is found 
to be 4 or 5 inches in length, showing a monthly rate of growth of about 
1 inch. From this time it gradually increases in size until the following- 
spring, when it becomes adult and capable of furnishing embryos for 
infection of other animals. These embryos escape from the sheep, and 
while many are destroyed a few arrive at their destination in a second 
animal. 

Disease. — The inlluence that the presence of Tamia fimhriata has on 
the life and health of its host is not inconsiderable. The ultimate loss 
is seen when lambs which should be fat and strong are not, and die dur- 
ing the colder weather while the fatter ones survive. This loss, where 
the hosts do not die, can not perhn])s be accurately estimated, but is 
nevertheless present, for thin, hide-bound, dwarfed sheep are not 
valuable for mutton, nor do they produce as much wool as they other- 
wise would. 

So slowly are the parasites hatched, so slowly do they grow, and so 
gradually do the symptoms develop, that the twnkv are present in con- 
siderable numbers and size before systemic disturbances in the lambs 
liresent themselves. An experienced ranchman will probably notice 
towards September that some of the lambs are not growing as they 
should. Later in the fall the symptoms increase. In ISIovember the 
lambs, which are by this time thoroughly infected with a number of 
strong, tenacious parasites, show the disease quite plainly. 

The disturbances finally shown are induced at first by the local irrita- 
tion produced by the worms attaching themselves to the villi of the 
intestinal walls and causing a greater secretion through their strong 
vermicular action. A continuance and increase of this irritation caused 
by the growth of the parasite and an accession of other parasites, 
finally excites chronic catarrhal intiammation of the duodenum and bil- 
iary duct. To these disturbances we must add those arising in the liver 
from a plugging of the duct by the parasites, which grow so large that 
they distend it to a comparatively large size. 

Dr. George C. Faville, in a report of the veterinary department of the 
State Agricultural College of Colorado for 1884, describes the post- 
mortem appearances of these animals as follows : 

Organs of thorax were normal. In the abdominal cavity I found the stomach filled 
with a mass of semi-digested loco leaves. The liver was normal in appearance ; gall 
bladder filled with greenish-colored bile. In the duct running from the gall bladder 
to the small intestines, I found a mass of tapeworms (Tainia expansa). The small in- 
testine I found filled with a mass of these worms, varying iu length from 6 inches to 



96 

5 or 6 feet. Tlie kidneys were iimiiKil in si^io iiud color, but upon bcctioii, I loiiud 
the ptlvi.s filled with a <;elatiiions material. The nuiseular isysteui was exeee<liiij'ly 
llabbyaiid pale in color. The body seemed to be absolutely destitute of fat. The 
urine was normal. The brain showed a slij^ht serous effusion about the base, and to 
a slightly greater extent iu the region of the medulla oblongata. There also was a 
slight effusion into the abdominal cavity. The only other change that could be found 
iu the brain of these sheep was a slight congestion of the arachnoid membrane. 

The above descriptiou is taken from so-called " locoed " animals, but 
applies equally well to ta'niie- infected sliocp. Of the many " locoed" 
animals examined, but one or two bave been free from ta'nuv, and in 
these the gall duets were thickened and enlarged as though they had 
at some earlier datebeeu infected. It is extremely difficult to separate 
the symptoms of the two diseases, and it seems to me that many cases 
of " locoed " aniuuils are victims of the tapeworm. That the ticnia iiuiy 
temlto produce depraved appetites and the morbid craze for a i)articu- 
lar food, is also a reason for suspecting that the loco disease may depend 
in part on the tapeworm disease. 

In Dr. Faville's description there is one point which deserves atten- 
tion, and that is the finding of a slight congestion of the arachnoid mem- 
brane. In specimens examined by the writer there seemed to be uo 
undue congestion, and the arachuoid membrane, Avhich is a vascular 
one, naturally looks red or dark colored. The brain symptoms of these 
animals are such as arise from antemia rather than hyperajuiia of the 
brain. 

In affected yearlings which are not suspected of eating loco more 
than other animals (all eat of the loco plants), the following ante and 
postmortem symi)toms can be observed : Lambs that are badly affected 
are large headed, with undersized bodies and hide bound skins. Their 
gait is slightly like that of a rheumatic. They seem to have difficulty 
in cropping the shorter grass; they also appear to be more foolish than 
the other sheep, standing oftener to stamp at the sheei)-dogs or herder 
than the healthier ones. Others do not seem to see as well, or are so 
affected that they appreciate danger less. In driving they are to be 
found at the rear of the flock. Internally the organs present no marked 
symi)toms of disease. The abdomen contains more dark-colored serous 
fluid than normal ; the omentum is often nearly devoid of fat. The ca- 
tarrhal inflammation and thickening of the mucous membrane of the 
duodenum and gall-ducts have already been noticed. The liver, in 
cases of long standing, is somewhat smaller than normal ; the kidneys 
are sometimes flabbier and paler than normal ; the lymphatics look 
somewhat darker; the muscles are thinner and weaker. There is in 
all cases a diminution of fat, and iu most cases the leanness of muscle 
is marked. In those places where the fat usually occurs in masses little 
or none is found. Associated with this condition is the presence of se- 
rous infiltration of the connective tissue in the abdomen, thorax, spinal 
and cranial cavities. This infiltration is the most marked in the worst 
cases. The groin, the pelvis of the kidney, the spaces between serous 



97 

coats of the iibtloiiieii, and other spaces where serous membrane par- 
tially or entirely suri'ounds an organ are noticeably inriltrated. 

These conditions hold in lambs and older sheep. Uetween the worst 
affected and entirely healthy individuals there arc many grades. The 
symptoms and pathologic lesions are those of malnutrition, and aside 
from the lesions of the duodenum and liver are not materially different 
from the sjstemic lesions caused by other parasites, or from innutri- 
tions food, or from any cause that would prevent the animals obtaining 
and assimilating nourishing food. A variety of other causes would 
produce the same lesions. 

The parasites may produce their evil results as follows : Their vermic- 
ular actions cause increased secretion of tlie intestine where they are 
lodged, both by direct irritation and sympathetically, /. t'., the adjacent 
intestine secretes more than it ordinarily would by acting in symi)athy 
with the infected portion. This hypersecretion soon becomes abnormal, 
and the secreting membranes become so changed that they can no 
onger act physiologically. Its best purpose is in furnishing the para- 
site with more nutritious fluid. The plugging of the gall (.lucts not only 
stops the gall from tiowing at proper times, but dams back that which 
is secreted during digestion, and allows it to slowly ooze out after it is 
needetl. When the ducts are unobstructed the bladder and ducts are 
lemptied at their proper times, and any interferen(;e with this flow 
deranges healthy digestion. The damimng back of the gall reacts on 
the secretion iu the smaller ducts, and this in its turn reacts ou the 
I)hysiological functions of the liver cells. 

The disturbance of digestion due to this impairment of the functions 
of the liver and duodenum has not a merely local effect. In the upper 
parts of the small intestine important digestive changes take place, and 
the disturbance of any of these prevents the proi)er i)reparation of food 
for its assimilation through the intestinal wall, resulting in a loss to 
the animal of nutrient material. The duodenum is held to be a very 
irritable organ, diseases iu it causing reflex disturbances of various 
kinds. These reflex actions also lead to many systemic disturbances. 
Now these disturbances are each slight, but when combined and con- 
tinued through weeks and months they cause the results just described. 
To one seeing a half dozen or more worms taken from the intestine of a 
sheep the worms do not seem to be a sufhcient cause of disease. The dis- 
turbance caused by one worm in man gives rise to even greater systemic 
derangements. The non-assimilation of food and reflex irritation pro- 
duced by the tape-worms seem to be the chief causes of the impover- 
ished condition of the infected animals. . From these causes proceed the 
imperfect nutrition of the various organs and the dropsical effusions 
resulting therefrom. 

From this state of mal-nutritiou all of the systemic disturbances can 
result. The staggering gait may arise from the weakened muscular 
system; the absence of fat from non-deposition of more and the cou- 
23038 A P 7 



98 

siiQiption of that heretofore deposited; the serous efifusions froiu the 
weakened condition of the system; and the foolish actions IVoni the long- 
continued lack of nourishment of the brain. 

Sheep do not die from the tape-worm disease alone. The greatest 
losses are, the ranchmeu say, amjng the lambs and yearlings. The 
majority may die during cold storms, either from freezing or from sutib- 
catiou while piling upon each other for warmth. They may starve to 
death either from inability or lack of desire to eat. They uiay die from 
other diseases. The tape worm disease appears to render them more 
liable to othei affections and less able to withstand the inclement sea- 
sou. It is therefore indirectly chargeable with the loss. Even if the 
infected sheep do not die, the parasite is still a cause of pecuniary 
loss. The impoverislied condition traceable to it is a small average 
loss for each animal, but for tlocks of over five thousand sheep the ag- 
gregate is thousands of dollars for each ranchman. 

In the article of Dr. Faville, cited above, he quotes a letter * from 
the late Hon. J. M. Givens, whose flocks numbered from six to eight 
thousand head. In this letter Mr. Givens states his loss from dead 
sheep alone for the preceding year at from $3,000 to $4,000. Fortu- 
nately the loss of from four hundred to eleven hundred or more sheep 
does not occur to tiock masters annually, but such losses are not in- 
frequent, and may be heard of either on this or that ranch during 
ditterent years. Every ranchman knows of and appreciates the steady 
though small loss arising from the dei)reciated value of his animals, 
due to their ill condition from various causes, and which he strives by 
every means to reduce, for therein lie the profits and success of his 
business. From the study and observation which the writer has been 
able to devote to the tape- worm disease it appears alone responsible for 
more losses than any other sheep disease on the prairies excepting 
scab. The direct death-rate traceable to it is large when compared to 
the entire death-rate, and the indirect loss traceable to it is, though 
more insidious in its character, still larger, for it is ever present and 
ever active. 

Medicinal treatment. — Some experiments looking toward the removal 
of tmiicv by medicines were made in 188G. Various ta'niaj'iKjes were tried 
with little success. The powdered preparations of pumpkin-seed, 
l)omegranate-root bark, koosoo, kamala, male fern, and wormseed proved 
of no avail. 

In order that they might be administered cheaply the proper amount 
of each for ten animals was mixed with meal, bran, and salt, and fed in 

*The letter referred to gives "loco" as a cause of the losses. Before his death the 
Hon. J. M. Givens had coucluded, and coniniuiiicated to his friends of the El Paso 
Wool Grower's Association, that the loss of this winter was uot duo to " loco," for 
the greatest loss had occurred in young sheep and lambs. The latter had uot learned 
to eat "loco" exclusively, were poor, and presented symptoms which he learned 
later belonged to sheep infested with tape-worms. 



99 

a trough. When sufficient meal and salt was mixed with the medicines 
to entice the sheep to eat it, the bulk that contained the requisite dose 
of medicine was too large for a sheep to eat at once. As this bulk was 
retained for some hours in the rumen, the efficacy of the dose was lost, 
for the virtue of nearly all of these remedies depends on the dose passing 
through the intestines in mass. Ilumau patients are usually prepared 
for the medical treatment by abstaining from food for at least twelve 
hours previously ; they are then given a cathartic which is followed by 
the anthelmintic. This plan of treatment utterly fails in ruminants, 
for neither stage can be successfully carried out in administering 
these remedies by the mouth. The presence of the large rumen, which 
holds a large quantity of reserve food, and into which new material may 
be taken, accounts in part for this. Some of the food, if sufficiently 
fine, in fasting animals passes directly to the manifolds and fourth or 
true stomach, but a certain proportion would fall into the rumen, and 
thus thQ efficacy of the total amount acting within a given time would 
be lost. 

These experiments failed, therefore, through the anatomical structure 
of the animal and the method of administration. The presence of 
twniw in the biliary ducts is another reason why tmimvfuges can not 
be entirely successful in treatment of sheep with T. Jimbriata. Any 
medicine which would affect the tamia; in these ducts would also affect 
the sheep seriously. It is doubtful whether they can be killed or driven 
from the ducts. The continued or repeated administration of remedies 
that are necessary for expelling these twniw is also an objection to 
their use. The parasites are continually appearing throughout the 
year, and even if those already developed could be driven off, the con- 
stant re-infection would necessitate other operations for their removal. 
The cost of the necessary medical treatment seemed to me to more than 
exceed the good results that possibly might be realized. Further ex- 
l)eriments were therefore delayed until the complete life history of the 
parasite should be determined. In this history we may hope to find 
some stage at which we may more profitably administer remedies. 
Many prescriptions for eradicating tape worms in ruminants are given 
in various journals and agricultural papers. Some of them when tried 
may have proved very efficacious. Unfortunately reports concerning 
the effects of their administration are not recorded. My own experience 
leads me to have little faith in them. There is a feature about them 
which, no doubt, has been recognized by the ranchman who has under- 
taken to carry thein out to the letter, viz : It is the entire inadequacy 
of the recipes in prescribing methods of administration, and medicines 
of reasonable price as well as of certain efficiency. This oversight is 
of such importance that otherwise good recipes have to be abandoned. 
The Western methods of treating sheep medicinally must differ from the 
Eastern methods, as the methods of sheep-dipping, sheep-shearing, or 
sheep-husbandry in these sections differ; otherwise the expense of 



100 

treiitmeiit will be so considerable that iu view of auy imceitaiiity of 
cure few raiiclimeu will undertake it. 

Preventive treatment. — The most eifective service rendered to man 
and beast by the physician has been through the prevention of diseases 
and the i)reservatiou of health by hygienic measures. Appreciating this, 
and that effective prophylactic treatment of the sheep against infection 
by Tcenia Jimbriata could not be realized except by the most thorough 
knowledge of the complete life history of the parasite, my attention was 
turned to the investigation of its younger stages and those of other un- 
armed ticnke which were available. Such are the difticulties of this in- 
vestigation that the gap in the life history, which may exist between 
the time when the embryo passes from the sheep until it is found, less 
than a tjuarter of an inch long, iu another sheep, has not been comi^letely 
iuvesti gated. 

From the i)resent knowledge of the development and life of this par- 
asite there have arisen more difficulties in forming rules of prevention 
than was at first anticipated. The presence of the adult and young par- 
asites throughout the year, and the methods of Western sheep ranching 
are factors which are all-powerful in keeping up the tape-worm disease. 
The case is not a hopeless one, however, for there are certain phases of 
feeding and watering the sheep which can probably be advantageously 
changed, both for the prevention of this and other diseases. 

The feeding occurs on the prairie and in the corral. 1 would recom- 
mend that the ewes with their lambs should be pastured on a portion 
of the prairie that had not been run over by sheep for some inonths 
previous. Thej' could be driven to the new pastures about the time 
that the lambs begin to nibble at the grass and drink water. After the 
lambs are weaned they should be changed to fresh uncontaminated . 
pastures uutil winter, and other older sheep put on the range vacated. 
If there be sufficient range the lambs could be kept on as nearly unin- 
fected ranges as possible uutil they become two-year olds. In feeding 
himbs on grain and hay measures should be taken to keep the food 
from the ground. The grain should be fed from troughs placed either 
on a board Hoor that could be cleansed or on ground kept scrupulously 
cleaned of all dropijings. The hay should be fed from racks. The 
corrals for the lambs should either be fresh ones or the old ones should 
be periodically and thoroughly scraped out and cleaned. They should 
not be put with a greater number of old sheep than is absolutely nec- 
essary. 

The watering occurs at various places. The usual method is the 
watering at rivulets or ponds. This should be done, but such places 
should be fenced in and troughs provided into which the fresh water 
could run. These troughs should be raised a little above the surface of 
the ground so that they could receive no surface drainage. By the aid 
of pumps and wind-mills this could be easily accomplished. Most water- 
ing i)laces are so situated that by conducting the water through pipes 



101 

or boxes but little expense would be uecessary to guide it into troughs. 
Tliese troughs should be kept clean. The lambs should not be allowed 
to driuk elsewhere, nor to eat grass in moist places unless it is abso- 
lutely certain that these places are uniafected. The location of corrals 
so that they either surround water or that the drainage is from them to 
the water seems to be a most harmful practice. It not only makes the 
water fouler but renders it more likely to hold parasites. Herders 
should be instructed neither to feed nor water at the prairie pools. If 
there are places where it is advisable to water they should be prepared 
like the watering places at the corrals. The nearer the ranchman can 
arrive at giving the lambs pure fresh water the less infected with para- 
sites will they become. The salt for the lambs and young sheep should 
be fed from boxes placed near water ]>laces and kept constantly full. 
They will take no more than they want and will be all the healthier if 
they have all they need. If they are deprived for a time they may at 
first salting eat more than is good for them. A little eaten daily is 
physiologically better than the larger quantity eaten at interva]s. The 
object of feeding the salt at watering places and from boxes is to keep 
them from licking the dirt where salt has stood and to keep them from 
eating the prairie alkali. In addition to the opportunities afforded them 
of being infected with parasites from the salted ground there is the in- 
jurious effect of the swallowed sand. This sand often packs away in 
the gall ducts and produces disease. 

It may be when the gap in the life history of Twnia fimhriata is 
known that a single measure of prevention will eradicate it from the 
flocks. Until then the general measures prescribed above are to be 
recommended. 

There are various minor precautionary measures to be fulfilled that 
will help affected sheep to live through the colder winter, and finally 
to render effective service in spite of the parasite. The post-mortem 
examinations have led me to expect that from 80 to 95 per cent, of each 
flock is infected. Now, were all of these to sufler as some of the more 
diseased do, sheep-ranching would be at its end. Fortunately a sheep 
may have a few parasites and not be seriously affected by them. This 
is shown by the fine, large sheep slaughtered which are passably fat and 
yet contain tccrikc. It is a frequent remark of the ranchman that if 
he could carry his lambs and yearlings through they would do well 
enough afterwards. It is these younger and growing animals that suc- 
cumb soonest to the parasite. It is a rule that all young and growing 
animals are more seriously disturbed by the presence of parasites than 
older ones. Young lambs born in May or June have necessarily but a 
short time in which to grow before the cold season. When food is 
plenty, and there is no disturbance of their digestion, or other ailments, 
they enter winter strong enough to endure the weather without partic- 
ular suffering. Interference with digestion, lack of food, or any ail- 
ments render the lambs so much the weaker, and consequently less able 



102 

to endure the winter storms. The parasites interfere with digestion, 
and to overcome their evil effect means should be taken to supply easily 
digestible and fattening food, which may replace and add to that lost. 
Many ranchmen already feed their lambs extra grain during the fall, 
and have learned that not only are their losses diminished, but that 
the lambs become larger and stronger as well as fatter. 

Formerly the ranchman depended, as many do still, entirely on the 
prairie for grass throughout the season. Of late years many are feed- 
ing more an<l more hay during the winter, and find that they profit by 
it in the diminished death-rate and the improved condition of the flocks 
in spring. Tliis fall and winter feeding is, then, to be especially recom- 
mended as a remedial measure against losses among tape- worm infested 
sheep. With increased i)rosperity, flock-masters are adding to their 
shedding at the home corrals. Though the first cost seems considerable, 
such are the evident benefits in preventing losses during the extremely 
cold snaps and blizzards, that not only should they be built at the home 
ranches, but also at the outlying ones where now, with few exceptions, 
none are to be found. 

The water atibrded sheep, more especially lambs, should, if possible, 
be made warm during the coldest weather. The temperature of sheep 
is about 1030 Fah. In giving them water which is less than 35^ Fall., 
the heat which is necessary to raise the water to the temperature of the 
animal is withdrawn from other portions of the body, and digestion is 
often disturbed and less water is drank. Experiment has proven that 
animals fatten better on warm water, and were it practicable no water 
cooler than G()o Fah. should be offered to sheep. The maintenance 01 
the drinking-water at this temperature for the use of the lambs and 
other home stock would jirobably repay the Western ranchman, as it 
certainly would the Eastern farmer. This is impracticable at some 
ranches, but there are many home ranches where lambs and blooded 
stock are kept at which the system might be pursued with advantage. 

There is another {)ossible chance of infection which there is no known 
means of remedying. If, as is probably the case, the tcenia embryo 
passes with but little modification from sheep to sheep, there is then 
a certain amount of infection that may occur between the ewes and ott'- 
spring when suckling, the lambs becoming infected with embryo by 
rubbing them from the mother in nosing around while suckling. As 
older sheep have the tivniw, and as lambs become infected after being 
weaned, this method of infection is oidy one of many. 

No medicinal remedies or preventives can be advised. The recom- 
mendations above are directed toward lessening the chances of infec- 
tion and preserving the health of the animals. 

It is hoped that the gaps in the life history of Twnia Jimhriata, or 
others of our unarmed ta'nicv, may yet be filled out. With a knowl- 
edge of this history, the methods of prevention would be evident to all. 

Thcllock master should take pains to examine the sheep which die and 



103 

inform himself, as nearly as possible, of the cause, of death. In case of 
the presence of tape-worms, causing sickness, he can soon inform him- 
self of their abundance, of the absence of other disease, and of many 
other things. He can soon Judge whether others of his dock have them, 
and can more intelligently set about their treatment. A careful study 
of each case will then place the observant man in possession of many 
facts which will help him in the proper management of his flock. 

The above recommendations have been written with a view of keep- 
ing the food and drink of the animal as clean as possible. Other pre- 
cautions will suggest themselves to the ranchman. 

Post-mortem examinations. — The tables herewith presented are the 
results of postmortem examinations of sheep, some of which were killed 
expressly for the purposes ofinvestigation. Others were examined while 
being slaughtered for food, either on ranches or at the siiambles in Col- 
orado Springs, Colo., wliile in other cases examinations were made upon 
dead sheep found either at or in the vicinity of various ranches. From 
the wide-spread distribution of the disease,- the notes are such as could 
be taken from nearly all localities, and can not be ascribed as purely 
local causes. Where the observations were taken from the sheep raised 
in States other than Colorado, the State from which they came is given. 

In addition to the presence of Tienia Jimbriata, the occurrence of 
Tcenia expansa has been noted, and also of Twnia marginata, which 
occurs in sheep in its cysticcrcal stage. The examinations at the sham- 
bles could not be conducted with the same accuracy while hunting for 
Twtiia, Jimbriata; the occurrence of the cysticerci is, therefore, omitted 
in i\\Q, post-mortem observations of June 7, 1887, to August 15, 1887, in- 
clusive. 

Table A shows that ketiiw occur in sheep throughout the year. It 
also indicates a wide-spread distribution. 



A. 



Dato. 


No. sbeep 
examined. 


No. lambs 
oxaniined. 


Location. 


T. fim- 
brlala oc- 
cnnod in- 


Ci/sti- 
cerci oc- 
curred iu- 


T. ex- 
paiina oc- 
curred iu- 


No. 
of ear- 
tags. 


1886. 

Si^pt.lC 

18 


1 
1 
1 
3 
2 
11 
10 
5 




Colorado.. 




9 

6 

1 








do . ... 


1 
1 
3 

9 

9 
4 
1 

2 
1 
8 
3 
3 
3 
1 
1 
1 


l 




21 




...do 




24 




...do 






27 




....do 






30 




....do 






Oct. 1 




... d,) 






10 




....du 






21 


1 
2 

1 


...do 

.. do 

...do 

....do ... 






29 


4 

2 
1 
8 
5 

2 

1 
1 


3 






;n 






Nov. 2 












....do 








4 




...do 








9 


1 
1 


...do 

....do 

do . .. 


1 
1 

1 






10 






11 






15 




.... do . . . 






16 


1 


. . do 









104 

A. — Continued. 



Date. 


No. slieep 
exainineij. 


No. lambs 
exatuiued. 


Location. 


T. fim- 
biiata oc- 
curred in- 


Cysti- 
ccrci oc- 
curred iu- 


T. ex- 
pansa oc- 
curred iu- 


No. 
of ear- 
tags. 


Nov.19 




1 
2 


Colorado.. 

...do 

do 


1 

2 
10 


1 


1 
2 




21 






22 


10 


1 




Dec. 26 


i 

1 
1 

1 


...do 


1 


105 


29 




...do 

....do 

....do 

...do 


1 
1 

1 
2 

T 

1 

1 

1 

*8 

10 

8 

5 

3 

2 

19 


1(17 


30 






100 


1887. 
Jajj 8 






108 


Mar 14 


2 
1 

1 
1 




103 101 


yg 




do 


1 




101 




1 
1 
1 


....do 

....do 

..do ...... 

Nehraslta. 
do 




10() 




1 
1 




102 


May ^ 




110 




8 
10 
10 
5 
4 






q 










13 




Utah 

Colorado.. 

...do 

...do 

.... do 










12 
4 
4 








Jnly 29 








Aug. 5 







Vi. Sc L. 


5 


20 




July 


1 
+4 


.... do 










4 


..do . .. 


3 
















Total 


136 


32 




139 j 42 


5 





* From June 7 to August 15 inclusive, cysticerei were found in moat of the animals examined. 
tNo tmnice fouw\ in the two lambs. 
X No tcenioi found in lambs. 



Experimentfi — N'ovembcr ^0, 18S6. — Six lambs, solected from a bunch that had boen 
kept in an inclosure since the 15th of October, were, with two yearlings and two two- 
year-old wethers, crated and sent to the United States Veterinary Experimental Sta- 
tion at Washington. The lambs were from a collection of the runts of a large flock 
which had been fed on hay made from prairie grass and on coarse corn -meal and 
brau before November 30. They were watered from tubs, the water being drawn 
from a well and a pond near by. The land on which the hay was grown had not 
been crossed by sheep since spring, at least. The water was clear. The chances of 
infection from these sources were small. The corral where they were kept was a 
good warm shed, located amidst others, with a small adjoining yard. The dogs, of 
which there were two and sometimes more, had free access by jumping the hurdles; 
but I do not remember ever having seen one in the inclosure after the lambs were 
admitted. With these lambs were two old bucks and a few sheep, which were either 
lame or otherwise ailing. They arrived in Washington, D. C, December 4, 1886, 
and were afterwards placed in stalls where they could not be re-infected excepting 
from each other. As Table B shows that thei'e were uo adult tcvniw in the lambs, 
reinfection could only be through the four older sheep confined with them. Rein- 
fection could not possibly have proceeded from some Eastern sheep confined with 
them, for these sheep, when examined, had no T. fimhriata. No dogs were admitt(!d 
to the box-stalls where they were kept. Their food was Eastern clover and mixed 
corn an.d bran. They were furnished with well-water and salt. The adults were 
numbered 101 to 104 ; the lambs from lOii to 110. 

Deccmhcr 9. — Two Eastern lambs, Nos. HI and 112, were put in the pen with Nos. 
101 to 110 inclusive. Nos. HI to 118 were a number of Eastern coarse-wooled sheep, 
bonght for ex})erinientail purposes. 

Deccmher V3. — Nos. Ill and 113 were found to pass mature embryo bearing proglot- 
tides of T. exxyansa. 



105 

December 17. — Fed Nos. 105, 107, and 109 with proglottides of T. expansa from Nos. 
Ill aud 113. 

December 31. — Lainbs Noa. 106, 103, and 110 were put in a pen with Nos. Ill, 112, 
113, and 115. Aud sheep Nos. 101 and 104 were put with Nos. 114, 116, 117, aud IIH. 
Later on some other changes were made, but as the Eastern sheep were found to con- 
tain no tamiw when examiued, these changes had no result, and couhl not have 
affected the result in other ways. 

The object of arranging and rearranging these sheep was to give 
possible chances of infection to the uninfected sheep. 

Table B is compiled from data obtained from lambs born in 1880 ; 
from four wethers, which, with six of the lambs, were removed to the 
experimental station in Washington, D. C, and from a few lambs 
born in 1887. The sheep marked M, killed June 25, was also adult. 

Table B shows that the Taiiia Jinihriata begins to appear in two or 
two and a half months old lambs, that they continue throughout the 
winter and gradmilly attain maturity as spring approaches. Each of 
the tables, A and B, shows that adult tape-worms were to be found 
throughout the year. 

B. 





Date. 


No. of 
lamb. 


Number 
Ufnifv 
fouud. 


Lcnstliofr.^«i^rirt/n. 


Age in 
weeks.* 


Time in weeks. 




From 
range. 


In 
Wash- 
ington. 


Oct. 21 


1886. 


A 

n 

c 

D 

K 

F 

G 

H 

I 

105 

107 

109 

108 
103 
101 
106 
102 
104 
110 

K 
L 

M 


Fi>w . . . 

Many. .. 
...do... 
...do .... 


i-."^" and undfT 

10"" and under. 

.... do 


23 
24 
24 
25 
25 
26 
27 
27 
28 
32 
33 
33 

34 
43 
45 
49 
50 
50 
51 
10-12 
10-12 






20 






29 ... 






Nov. 9 








10 


3 








IG 


Many... 
. . do ... 
...do 


10"" aud under 

...do 




]9 






21 


....do 






25 


. . do 








Dec. 20 


4 

19 

100+.... 

Many. .. 
50+..,. 
Many. .. 

25 

15 

.5 


2"> 


10 
11 
11 

12 
22 
24 
27 
28 
28 
29 


4 


29 


irn, to 4'!"' 


4 


30 


5"'"' to IC"' 


4 


.T.in. 8 


1887. 


]c,n \q 7cin 


G 


Mar.14 


Immature aud adults 
.. do 


15 


29 




17 


Api-. 20 


7''" to 15'^"' 


20 


28 




21 


28 


do 


21 


May 7 


1 

2 

2. 


Adult 

2cin 


'J3 






5 


.. do 






June 25 , 


Many... 


2cm to 5cm adult . ... 

















'The age i.s that of the lambs aud is estimated May 15. 



I*^os. 101 to 104 and M were adult sheep ; all others were lambs. 
Adult tccniai coutained embryo. 

Fost-mortem examinations — December fj6. — No. 105 died. It contained four small 
Ta'nia fimhriaia, the largest about 2^'" long, and iifteen cysticerci of T. marginata, each 
less than l*^"" in longest diameter. 



106 

December 20.— K\\]od No. 107. It contained nineteen Hmall T. fimhriata, the largest 
about 4'"' in length, and twenty cysticerci, the largest a little over 1"" in diameter. 

December 30. — Killed No. 109. It contained over one hundred small twniw, ranging 
from 5""" to 10"^'" in length; also a few small cysticerci, apparently of same age as in 
107. 

January 8. — No. 108 died. It contained throe specimens of TwHia cxpansa ; one of 
these was adult ; many small T. fimhriata, varying l'"' to 7'"' long; also six cyi^tieerci, 
somewhat larger than tiio earlier found. 

April 20. — Killed No. 10(5. It contained many T. fimhriata, over twenty-live in all, 
which were over 7"" in length ; none were smaller. The duodenum and gall ducts 
were packed. None were adult. 

May 7. — Killed No. 110. It contained one adult T. fimhriata and several cysticerci. 

March 14. — Killed No. 103. It contained from lifty to sixty tunia from 7'"' to 10'"' in 
ongth ; four of those were in the gall ducts and were among the largest in size. l\v.- 
nia: immature to adult. 

March 29. — Killed No. 101. Found tivnid' in duodenum, gall ducts, and i)ancreatic 
ducts. The gall ducts were engorged; the liver smaller than normal. Thu twniie 
ranged in size from 7''" to 14''" ; three were adult. There were three cysticerci. 

April 28. — Killed No. 104. Found live taniia' from 2"" to 4"" in length, but no cysti. 
cerci. 

April 28. — Killed No. 102. Found Gfteen twnUv. The largest were not over 7"" in 
length, and immature. There were two csyticerci. 

Table C is made up from data obtained from the six lambs, .Nos. 
105 to 110, inclusive, transported from the prairies to Washington. It 
shows the comparatively slow growth of the parasite; also the abun- 
dant infection of some of the animals so long as they were exposed to 
infection. It also presents either the ]>ossibility of infection after they 
were taken from the prairie or the retention of the embryo in the rumen 
through a considerable time. 



O. 



Date. 



Dec. 26 
29 
30 
Jan. 8 
Apr 20 
May 7. 



No. 


A<;e in 
weeks. 


No. of 

Tceiiia 

Jimbri- 

ata. 


105 
107 
109 
108 
106 
110 


32 
33 
. 33 
34 
49 
51 


4 

19 

100+.. 
Mauy . 

?5 

1 





Weeks 


Weeks 


TcenicB 


after 


after 


size. 


October 


Decem- 




15. 


ber 1. 


Centimeter. 






•> 


10 
11 


4 

4 + 


1-4 


0.5-10 


11 


4+ 


1-7 


12 


G 


7-15 


27 


20 


Adult 


29 


23 



Weeks 
after 
Uecein- 
ber 31. 



October 15, tbe date on whicb tho lambs wore taken from tlio prairie and coirallod. 
December I, tbe date on whicb the lambs were received in Wasbiugton. 
December 31, the date on which tlie adults, Nos. 101 to 104, were removed. 



Lambs K and I, Table B, sliow that the trvnia was developed to a 
length of 2"" in less than ten or twelve weeks, for the number of ttvuitv 
found shows a slight infection and some time may have elapsed after 
the birth of the lamb before its infection. 

Lambs A to [, Table B, show that in from twenty-tiiree to twenty- 
eight weeks the ticnitt, may develop to 8 or 10"" in length, and that the 



107 

infection is proportional to tlie time exposed. The infection is, how- 
ever, a variable quantity, and no definite statements can be deduced. 

As the lambs do not begin to nibble grass and drink water until some 
few days after their birth, the development of twnia in K and L prob- 
ably required not over two months. Lamb A, examined October 21, 
about twenty-three weeks after birth, gives, when compared with K 
aud L, an approximate rate of growth of the twuia of 2'"" a month, 
more or less. The rate of growth must so vary at different times that 
no definite rate can be determined at present. 

The keniw of No. 105, one of the same lot of Lambs as the foregoing, 
were no larger after thirty-two weeks than those of K and L after ten 
weeks. This points to a recent infection of No. 105, i. e., within ten 
weeks, or about the time the lambs were taken off the prairie and re- 
ceived into the corral. The twuicc of Nos. 107, 109, 108, and lOG coin- 
cide with this ; but the lambs No. 109 and 108 also poitit to a later in- 
fection, as nuiTiy very small tamicv were found in them. No. 108, which 
had td'niw 1"" long six weeks after its receipt in Washington, would 
lead us to suspect a recent infection ; but this is not necessarily the 
case, as the influence of the rumen of the sheep in detaining the para- 
site for a length of time has yet to be learned. The absence of young 
twnio} measuring less than 7<"" in No. 106 at sixteen weeks after its 
last association with an animal containing adult Uvnicv and twenty 
weeks after its arrival in Washington is also of interest in that it points 
to infection of the lamb from the adult sheep associated with it. No. 
110 shows a very slight infection, and one, judging from the age of 
twnicv, that could have occurred in Colorado. 

The six cases show a slow growth of the parasite ; they also point to 
one of two things: That the twniw are, as embryos, retained in the 
rumen for some time after being swallowed, or that these tceniw are 
continually infecting their hosts by the direct method ; that is, the 
embryos passed by sheep, with little or no preparation, pass into other 
sheep and develop without the intervention of an intermediary host. 
So far nothing has been found to absolutely prove or disprove the latter 
statement. The infection, as shown by the various sizes found in these 
lambs and other sheep, points to a continuous infection nearly all the 
year. (See Tables A, B, and C.) 

Nos. 100 and 110 indicate a cessation of the infection for the length 
of time it required the smallest (7*^'") to attain their size. Lamb A in- 
dicates the time to be something less than twenty weeks, or at the 
period when they were received at Washington. Nos. 106, 107, 108, and 
109, which had been confined eleven and twelve weeks, show as great 
infection as has been seen. This would happen with animals which 
were being infected in confinement, for the opportunities of infection, 
if the infection should prove to be direct, are greater. Various condi- 
tions, as the weather, food, water, etc., have so much to do with the 
problem of infection that far more data are necessary. 



108 

The fact of slow development atul continuous infection are the main 
points brou<;ht out in this experiment. Continuous infection is natu- 
rally one of the results where twniw are constantly developing and 
shedding ripe proglottides laden with embryos for the infection of other 
hosts. Continuous infection also leads me to suspect that no" interme- 
diary host is necessary for the contiiaiance of the life of the embryo. 
This proceeds from the fact that !io single species of mollusk, insect, or 
other animal is to be found at all seasons and places necessary to suit 
all the conditions under which we tind the host infected. 

Experiment No. 2. — A lamb dropped at a slaufrhter-houso in this city was kept witli 
its luotlier in an nninfected stall. 

Tlio 1 inib was fed on Jaunary 10, 1887, with a largo quantity of proglottides of 
Td'nia expausa from No. 108. The embryos were found to be alive and moving before 
feeding. 

On March 20 the same lamb was fed with proglottides of T. fimhr'mia from No. 10:?. 
These contained live embryos on the 18th instant. 

On March 21) fed the same lamb with proglottides coutainiugembryos of r._/(»i7>r(rt7rt 
from No. 101. 

On April 11) this lamb was killed and nothing was found except a few white spots 
iu and ou the liver. The experiment had uo results. 

AN EXPERIMENT TO INFEOT LAMBS WITH TiENIA FIMBRIATA. 

Experiment No. 3. — May 23, 1837, placed fifteen ewes with unborn lambs in three 
box-stalls. They were fed ou .alfalfa, haj^, corn, and bran. Their water was drawn 
from a hydrant near by. The ewes being thin in llesli, and taken from the prairie 
grass and placed upon dry feed, thrived but poorly. Between May 23 and May 29 
eleven lambs were born, which lived until the close of the experiment. Five of the 
largest and oldest were placed with their mothers in stall No. 1. The remaining were 
divided between two stalls, Nos. 2 and 3. 

These animals were removed from all sources of infection through 
food and water, and the lambs had never been exposed to any source 
of infection. The ewes were susi)ected of being infected with T.Jini- 
hriafa. If the lambs became infected they would either take them of 
their mothers or from their feed. Between May 2G and June 15 the 
lambs were fed in stall A several times each with a number of ripe 
proglottides from adult Uvnuc. An interval was left between each 
feeding, and each lamb was fed at least three times. The other lambs 
were not fed. All but two of the ewes were found to contain adult 
ta'nia' when examined later. 

The lambs and ew^es were killed in nearly equal lots on June 25, July 
15, and August 1. 

.Tune 25, killed one ewe and one lamb from pen No. 1, two ewes and one lamb from 
No. 2, and three dry ewes from No. 3. Lambs uninfected. One ewe had twnia^l'^"^ 
long. 

July 15, killed two owes and two lambs from No. 1, two ewes and two lambs from 
No. 2. Lambs uninfected. 

August 1, killed two ewes and two lambs from No. 1, and two ewes and two lambs 
from No. 2. Lambs uninfected. 



109 

The lambs were kept for two months, and were not infected in this 
time. This experiment shows that either a longer time is necessary for 
infection or that the embryo has to nudergo some develoi)mentor prep- 
aration that was not allowed and of which we are ignorant. The speci- 
mens fed were taken from slaughtered sheep, examined with a micro- 
scope, and fed by placing the proglottides which contained living 
embryos in the lambs' mouths and waiting until they had been swal- 
lowed. 

The lambs while living with their infected mothers should have been 
infected, providing infection by embryos fresh from the host be possible. 
As this was not the case, further preparation and development of the 
embryos outside of the ovine host seems necessary. 



110 



TAENIA FiMBUiATA, Diesiug. 
Plate XII. 

Fig. 1. Adult, uatiiral size. From coutiacted alcoUoUc specimen. 

Fig. 2. Head, edge view, XC 

Fig, 3. Head, side view, XO. 

Fig. 4. Head, top view, X6. 

Fig. 5. Portiou of segment : a, genital pore ; h, cirrbus i)oucli; c, seminal appara- 
tus; d, the efferent tube; e, the rudimentary uterine apparatus; /, vagina; 
</, tbe receptacle of tlie semen ; 7(, iimbria'. 

Fig. G. Portion of segment. more mature than Fig. 5: a, genital pore; b, cirrbus 
poucb ; d, efferent tube ; c, tbe uteri. 

Fig. 7. Tbe uteri enlarged. 

Fig. 7a. Tbe uteri still furtber enlarged, sbowing tbe contained embryo. 

Fig. H. A balf-grown tienia, sbowing tbe fimbria^, X2. 

Fig. 9. Fragment of ttenia from near bead, sbowing tbe lateral excretory vessels. 

Fig. 10. Terminal portion of adult, X2: a, segments wbicb bave lost tbeir contractil- 
ity ; b, separated segments. 

Fig. 11. External reproductive apparatus, X40: «, genital pore; &, cirrbus poucb; c, 
penis. 

Fig. 12. Adult segment sbowing tbe symmetrical arrangement of tbe reproductive 
apparatus: a, a, genital pores; b, b, uteri; c, c, timbriu-. 

Fig. 13. Embryos as tbey exist in tbe uteri : a, a, envelopes ; b, b, embryo. 

Fig. 14. Embryo sbowing envelope and its six books. 

Fig. 15. Youngest tienia found. Natural lengtb indicated by lines at tbeir sides. 
All specimens except figures from 1 to 4 and 15 were drawn from fresb jireparations. 



PLSTE XII 



% 



:f^if''--p^ 



4 



■"--,, A 



,, -ix'^M'mi.'^^^"- - . ^ 



%v "^^ 






Imm^. 



V 






/"X 



t' M 



Geo. Marx, del. 



14 



H 










-^ "wrf 



P ^\\ 




w^wp^aWWvi?! dV 'ftf^lM'^ikkv/^JA 



TAENIA FIMBRIATA. 
(The Fimbriate Tapeworm.; 



L.Ho*?i. A Co, i.tU. . linhJi 



112 



TAENIA PiMEiiiATA, Diesiug'. 

Plate XIII. — Diesiuy's original ligiues. 

Fig. 1. Adult, naturjil size. 

Fig. '2. Head, side view. 

Fig. '.i. Head, top view. 

Fig. 4. Segments near bead. 

Fig. 5. Segments further removed from bead. 

Fig. 6. Some still more remote. 

Fig. 7. From near eud. 



PLffiTE XIII 



iy;ffI?T)T*n*m(j, 



]'!| 






"wmr 



Wjti^jet''i'^- 



A 



Ck^ 



_ < 












^H'^A'V 



/VWI'VVX'VWWVVI \iV\ U ^ a'' 1 . V\''A 




Greo. J/arx, del. 



TAENIA FIMBRIATA. 



..I a. To. l.illi B--iU" 



THE BROAD TAPE-WORM OF SHEEP. 

T^NIA EXPANSA, lllltl. 
Platea XIV and XV. 

Tcviiia expansa, the Broad Tape- worm, is one of the best known of the 
internal parasites of sheep, because of its flatness, leugtli, and hirge 
size. In summer and fall it is quite abundant. The amount of pecun- 
iary losses occasioned by its ravages depend upon the season and its 
abundance in affected flocks. It was introduced into tliis country from 
Europe along with tlie imported flocks wliich harbored it. Since then 
it has been parasitical on our flocks from generation to generation. It 
is now distributed from the wooded hillsides of New England to the 
grazing lands of Georgia, over the fertile prairies of Ohio, Illinois, Iowa, 
and Nebraska, and the boundless prairies, basins, and mesas of Colorado, 
Utah, California, and Oregon ; in short, over every sheep-grazing local- 
ity in the United States. Reported outbreaks from this vast extent of 
country are comparatively few and scattered, but are sufficient to warn 
us that when the pastures become narrowed, older, and overstocked, we 
may expect the same trouble with this and other x^arasites as has been 
experienced by sheep raisers through all time in the more densely pop- 
ulated districts of other countries. 

JJescription. — The entire worm measures in length about 5 yards, and 
in width from one-twenty-titth of an inch at the head to a half or three- 
quarters of an inch at the tail. Its thickness is from one-tenth to one- 
twelfth of an inch. These dimensions vary greatly, depending on the 
contracted condition of the worm wheu measured and on its state of pre- 
servation. Adult specimens taken from sheep may average less than 4 
yards, or may slightly exceed 5 -, but they never, in this country at least, 
attain that gigantic measurement of 100 feet ascribed to them by Eu- 
ropean observers. The head is somewhat larger than the neck, and 
measures one-twenty-flfth of an inch in width. It is smooth .on the end 
and has its four suckers directed anteriorly. Its neck, or that portion of 
the worm immediately succeeding the head, which is uusegmented, is 
shortor lacking. The body of the worm is apparently made up of a series 
of very short but extremely wide joints, which vary in length and width 
in the successive portions of the body. Tlie first rings of the tcenia are 
very short and narrow; the others are longer, but are always broader 
than long. Those segments wUicU are about two thirds the entire length 
2303a A ?— ^8 U3 



114 

from the head are the longevst. From these to the end they become grad- 
ually shorter and wider. In width tlie segments gradually increase from 
the head to the end. When first collected the texture of the worms is 
usually opaque and white, and it is only by allowing them to stand in 
water that they become transparent enough for study. It can then be 
seen that each segment is bilaterally symmetrical — that in each half is 
an independent set of genital organs. These become apparent at a little 
distance from the head, but show in their best development about half 
the entire length from the head. From this point on the segments be- 
come more and more opaque to the eiul. The genital organs lirst appear 
as a little horizontal line on each side ; gradually a little rosette grows at 
the end of each line; these disap[)ear and the segment becomes filled 
with the young eggs or embryos, which form the opaque mass. The ex- 
ternal genitals consist of a round pore on either side of each segment, in 
which is a miiuite dot, the opening of the vagina, and an exserted in- 
tromittent organ. The ai)paratus is called hermaphroditic, i. e., each 
half of the segment is capable of fertilizing itself; but it is likely that 
cross fertilization also occurs. Fertilization occurs about where the 
dots which line each side of the worm a[)pear plainest. From this 
point on the eggs are develo[)ed into embryos until the end of the worm 
is reached, when the segments are prepared to retain vitality as indi- 
viduals for some time after being ejected with excreta to the ground or 
water. 

Besides the reproductive apparatus there are two so-called excretory 
canals, one on each side of the worm, running the entire length. I 
have not observed cross-canals, such as occur in the armed f(vni(v, as in 
T. mar(jinata. 

There is no alimentary canal. The nervous system is very rudiment- 
ary, consisting of little more than bundles of nerve fibers. The suck- 
ers are each supplied with their special fibers, connected together, and 
each segment is supplied b}itwo long nerve bundles which run parallel 
to the excretory vessels on either side. Absorption of nutrient material 
or feeding takes place through the surface of the segments. 

The young eggs or embryos are polyhedral by pressure, and measure 
about 0.05 to 0.07""" in diameter. They have usually two envelopes, 
between which a considerable amount of oily material is held. They 
may have three such. Around the embryo is a pear shaped a{)paratu8 
whose small end is surmounted by a cai) with shredded perii)hery. The 
embryo itself is contained in a cavity in the large end of the pyriform 
covering, and when alive can be seen moving around in it. The em- 
bryo seems to be a highly refrangent mass of protoplasm provided with 
six hooks, ami does not look essentially different from the embryos of 
other tape-worms. The cap with shredded edges is tlie remnant of a 
mass which originally included and covered the embryo and its balloon- 
like expansion. No attempt has been made by the writer to work out 
its earlier embryology. 



115 

The next stage of the embryonic t(vnia foiiod was taken from a lamb. 
In this stage the young worm (about-""" long) is well outlined. It had 
a head with four suckers and a short unsegmented body. The next step 
in the development showed the body segmented. In one or two speci- 
mens I have seen a little loop with its convex end projecting towards 
the outside, but hav^e not yet been able to determine its significance. 
Between these stages and the adult the different steps of development 
are easily filled in by a study of a single worm. 

Occurrence and (Usfrihution. — Although there is a periodicity in the 
appearance of the broad tape- worms anu)iig lambs, causing at times epi- 
zootic outbreaks, the worm may be found throughout all months of the 
year in localities where it occurs. No section of the United States 
seems to be entirely free from it. They have been found in winter, in 
spring, in summer, and in the fall, in tlie intestines of Iambs examined 
at the abattoir. They are not so frequent in winter and early spring as 
at other times, but seem to be more abundant in some localities than in 
others, though this may be due to uneiiual 0[)[)ortunities of observation 
in all places. A less number was found in the West than occur in the 
East. Conditions of climate and soil also seem to have some influence 
on the appearance of the tape-worms. Damp, warm climates and 
heavy, moist soils appear to be more favorable to their preservation 
while on the ground. But none of these factors would seem so favora- 
ble to the growth and life of the twnia as holding the sheep on over-fed 
pastures, as demonstrated by experiments elsewhere related. 

Differential description. — Toenia expansa differs from T. fimbriata in 
the method of shedding its segments. Instead of maturing a few of 
the segments at a time and shedding them, as the latter do, whole sec- 
tions ripen and pass away, so that an examination of a sheep which 
lias been observed to pass proglottides during a past week will reveal 
but little more than the head of a worm. The exact length of time that 
is consumed by the worm in maturing, so that it all passes away, is 
undetermined, but it is nevertheless an important factor in the disease, 
for after the worm is passed the lambs begin to recover. From what 
was learned and seen of the disease the opinion was formed that the 
worms do not retain their adult size more than a month. The heads, 
which are left, develop slowly and form new adults. They may not 
cause so much disturbance at this time, however, for the lamb becomes 
older and better able to withstand them. 

The rate of growth of the broad tape- worm is very rapid as compared 
with that of Toenia Jimhriata. This is easily demonstrated by the fact that 
T. expansa are found 2 to 5 yards long in lambs from two to four months 
old, while T. Jimhriata are scarcely, as many inches long in lambs of the 
same age. If we suppose the lamb to become infected during the first 
mouth of its life, the age of the taenia in the above lambs would not be 
over three months, which would give an average growth of nearly a 
yard per month. This enormous increase in size is an important factor 



116 

in rapidly developin<>' disease in the young lambs. The T<cnia fimbri- 
ata, on the (contrary, slowly develoi)s a disease which culminates in 
older lambs. 

Life history. — The life history of Tania expanm is only incomplete 
in that ]K)rtion of its life which it passes outside of the host. Just 
exactly what hapi)ens to the embryo-containing- egg, between the time 
fhat it escai)cs until it is again found in sheep as a little head with 
four suckers and a short tail-like appendage is not known, but from our 
present knowledge may be inferred with a tolerable degree of accuracy. 

No one has yet been able to either develop these embryos in water 
or to feed them and produce an infection in sheep. So it has been sup- 
posed by reasoning from the life history of other forms of tienm, that 
these embryos must pass a portion of their development in some of 
the minute animals which inhabit the grass and water of sheep farms. 
From my own studies, although I have not yet been able to produce 
tape- worm disease by feeding the embryos, 1 think that the above view is 
fallacious, and that these embryos need not pass any of their existence iu 
other invertebrates. Dr. F. A. Ziirn {Die Schmaroizer, p. 101, 1882) is 
authority for the statement that " the disease is also present in sheep 
which have been fed entirely in the stalls, though more especially 
among the younger and youngest of a herd which are sent to the 
pastures." 

Experiment to demonstrate method of infection. — About the middle of 
May, 1888, six lambs, from three to four months old, were bought on 
the market and added to the Hock at the Experimental Station of the 
Bureau. This flock was kept in a small stable with an adjoining hill- 
side yard. They were fed on clover and grain from the market, and the 
water was drawn from a well near at hand. The yard was sufticiently 
large to be grassy, but they soon ate it down to the roots. In one cor- 
ner of an adjacent pen was an iron trough, kept full of water. After 
a rain the water might have stood iu the yard for a day or two iu a 
small puddle, but there was no so-called permanently standing water 
which could have harbored insect life. There were already on the 
place three lambs, with their mothers, which had been raised there that 
season. 

May IG. — Two lambs wero fed by dreucliiiig with the embryos or eggs of Twuia ex- 
pansa. 

May 22, — An irou trough was prepai'ed with Ji grass bottom, and theu tilled with 
water. A quantity of segments of T. expansa were scattered iu it, and at tirst only 
two of the lambs were allowed access to it. Afrerwards, all were allowed to go and 
driuk out of it. 

June 11. — Slaughtered one of the Iambs, which had been drenched with T. expansa 
embryos May l(i, and had since been held in the yard with the trough prepared on 
May 22. No Iwniw were found. The experiment was therefore of negative value. 

After these dates the lambs were neglected, so far as feeding experi- 
ments were concerned, until fall. 

June 21. — One of the experimiMital lambs, which had previously been fed with ripe 
segiueutB of T. exiyanm, Avas killed. It was in poor condition, No to^vA9 were found 



117 

in it, bnt nninerons scars of T. marf/inala furrows ou tho surface of the liver. It was 
also found that numerous white patclies, which were scattered along the mucous 
coat cf the small intestine, were due to a species of coccirfm. As the latter disease 
has not been seen since that time, and as there was a possibility that the lamb had be^ 
come infected with the coccidia from the dirt thrown out of neighboring rabbit pens, 
where the disease was abundant, it has not ^nce been studied. The results, so far as 
T. expansa is concerned, were negative. 

October 10. — A ewe lamb was examined which had died some hours previously ; but 
one cysticcrcus was found. 

October IS. — A young buck lamb was examined, which was bought in May with his 
mother, soon after birth, from a neighboring slaughter house and was one of those 
which is referred to as raised on the place). There were found a ([uantity of young 
twiiiae, many adult and young of StroiKjylus contortux, a few young I>och)nias, and a 
few Tiichocephahis. This lamb was one of the two that was drenched with eggs on 
May 16. He had pastured with the others, which it was subsequently learned had 
adult twnia, and which had been purchased supposing them to be infected. 

October 9. — A buck lamb was examined, one of the six purchased in May. Old 
cicatrices of Taenia marginata were found in the liver, six Cysticerci of this species, 
two adult and six young Twnia expansa, a quantity of young .and old Slroiujylus con- 
tortun, and a few specimens of Triclwcephalus. 

October l(i. — A buck lamb, another of thesix, was found to be infested by a quantity 
of very youug twnia, also by young and old SirongyJus contortus, Dochmius, au<l Tri- 
chocephalns. 

October 17. — Another of the six animals bought in May was found to contain youug 
and adult Twnia expansa, Strongylas contortus, Dochmius, and Trichocephalus. 

January '.i, 1889. — A lamb slaughtered for examination was found to contain three 
Twnia expansa, one Cysticercns, and many specimens of Stromjylus Jllicollis. 

The period which had eLapsed from the time that these lambs had been 
received on tlie ])hice. to the period when the majority were examined 
(from May to October), was about live months. Those first liilled gave 
negative results, jirobably because they were examined too soon after 
feeding. The lot examined in October gave very positive results. 
The worms found in them varied from very young to adult. The small- 
est and youngest are those shown on Plate XV, figs. 8, 9, and 10. These 
were not fed to the sheep, for lambs which had not been fed were in- 
fected ; but the majority of the young tape-worms were acquired and 
developed after the sheep came under the experiment. This is amply 
proven in the case of the young buck bought and put with its mother in 
the experimental yard before the former was two days old. That the 
time of development of the adult worm is less than four months was also 
proven, from the fact that other lambs, less than four months old, ex- 
amined in May at the slaughter house, contained adult tape-worms. 
The lambs, therefore, acquired those parasites on the place. The ques- 
tion of the necessity of an intermediary host is also settled by this ex- 
periment, for none of those invertebrates, which are usually suggesied 
as being the intermediary bearer, were present at any time ; nor were 
the conditions which are essential to the life of many such invertebrate 
hosts present. The pasture was and is a very dry hillside yard, from 
which the grass was eaten very close by the sheei>. 

There is another phase of the question which is still in doubt. Early 



118 

in the experiment sej>'inentsof tape-worms were placed in an iron troujifh 
ontof wliicli the sheep <lrank, or conhl have drunk all sniiimer l()n<>- ; 
and there might have been times when, for a day or two, a little puddle 
of water could have collected after a rain. In these, more especially 
the former, the development of ,the parasites could have proceeded 
nntil they were taken up by the huubs. The point in doubt is, whether 
the lambs got their embryos from the water or from the yard while 
grazing. I am inclined to believe the latter, for they acquired other 
species of worms which were not placed in the iron tank, and these were 
also in various stages of development. Still another feature inclines 
me to this view. If the lambs had been infected from the iron tank 
they would viry likely have been infected by a large number of twnicv^ 
all of nearly equal size; but they were not. Direct infection has been 
tried before, but only negative evidence obtained. The failures prob- 
ably arose not only from expecting results too soon, but also from not 
preparing the infecting material ])roperly. 

Since writing the above, two lambs have been examined, which give 
additional data : 

August 10, 1889. — A five nioiitlis old lamb wiis examined, wiiicU liad been born at 
the experimental station, and kept there nnder the same conditions as the other 
lambs, i. e., water supplied from a pump and pasturage from the yard and lane near 
the sheep pens. This lamb contained two adult Tiv.niae, and Slrotujuhis contortus, S. 
flicolUs, S. vcniricosus, Dochmius cenuius, Trieliocvphalun affiuis, and (Esophafjostoma 
Cohimbianum, in all stages of growth. The last species did not show adults. 

August 10. — Examined a lamb eleven weeks old, which had been bought with its 
mother from a neighljoring slaughter house when two days old. Tiie lamb had been 
kept under the same contlitions as above. There were found one adult Tivn'm (shed- 
ding proglottides carrying well-developed six-hooked embryos) and all the other 
species enumerated above, but not in the same abuudanc(\ Ea(;h of these lambs 
showed that the infection had been continuous. The elder of the two yielded a 
greater number of S. filicollis than any sheep hitherto killed, and led me to think 
that this species may have been productive of more trouble than had hitherto been 
suspected. 

The above experiments were planned with an aim to obtain infection 
within a limited area, and under conditions which could be controlled, 
deeming it better to obtain infection under such conditions, though 
there be a number of them to complicate the (piestioii, than to restrict 
the conditions and not get an infection. 

The presence of the adult f(vnia in the com[)aratively young lamb of 
eleven weeks shortens the limit of time of complete development of the 
t(V)iia. The td'uia was about two yards long, a-nd had developed inside 
of three months. A reason for the early infection of this lamb was that 
its mother died and left it to shift for itself. Tliese expei'iments con- 
clude theseries fordetermining whether sheep necessarily getthe worms 
from drinking water or from tlu^ i)asturage. 

{^iim)iu(r)/. — The life history seems fiom the above to be a compara- 
tively simple aifair. The embi-yos pass from sheep to shee]) and develop 
into adults, which reproduce young for infection of other animals. 



119 

Whatever cbauges the embryos may pass thronoli outsi(U> the sheep 
can have little to do with the case as far as a kuowledge of prevention 
of infection goes, for bnt very few of the conditions nnder which these 
sheep were kept can be improved by the flock-master. 

Disease.— ThQ tape- worm disease can be diagnosed by finding the lit- 
tle white oblong tape-worm segments which are voided from the sheep 
and stick to the moist pellets of dung. They may also be found adher- 
ino-to the wool and dirt around the tail. But this is only after the 
tape-worms have become adult and have begun to shed segments. 
Tho.K-h sheep often harbor tapeworms and give no evidence of their 
presence until after slaughter, there are other cases in which their pres- 
ence is oulv too evident to the flock-master. Tl.e first indications of 
the disease are usuallv nnobserved, because of the slow growth and ot 
the comparatively- small number of parasites that may be developing. 
The time of growth occupies about two or three months from infection. 
The number of individuals maybe from two or three to a hundred, but it 
is nnusual to find more than a half do/en adults together. As many as 
fourteen adults were found in a himb four months old. \\ hen young 
they occupy bnt small space, need little food, and cause few vermicular 
contractions. In the earlier stages it is plain that they cause but little 
trouble, bnt when they grow so large that they seem to till the whole of 
the small intestines they cause the serious disturbances ascribed to them. 
These disturbances mav be to a certain extent those arising from a re- 
flex irritation of the sympathetic and spinal nerves, but most ot them 
seem to be due to the indigestion which the worms produce. The worms 
obstruct the intestinal canal by their great mass, irritate it by their ver- 
micular contractions, cause excessive secretion of intestinal fluids, non- 
assimilation of food, and abstract nutriment from the intestinal con- 
tents for their own growth. 

The lambs become poor and hidebound; their flanks may either be 
distended by gas in the bowels or be tucked np from ganntness. 
Iti the nrogress of the disease the animals become evidently weaker, 
the mucous membranes paler, and the fleece dry and harsh from the 
loss of its yolk. The animals walk with a tottering gait. They often 
eat more and drink oftener than those less attected. In the severest 
cases the lambs grow extremely weak and poor, diarrhea becomes more 
and more pronounced, and at last they die through slieer exhaustion. 
While suflering from these worms tiiey are more susceptible to the at- 
tacks of other parasites, and other diseases supervene and hasten the 

death of the already weakened animals. 

Pro^,i0.sw.— Though the tape-worm disease in its mildest form is very 
destructive to lambs and yearlings, yet it would seem that if they are 
able to pass safely through a certain period they are very apt to re- 
cover. In 1887, in the examination of two wethers which two weeks 
before had been passing proglottides, or segments, in abmdance, and 



12a 

from wliicli it was expected to seeuro specimens for illustration, only 
a small i)iece of the worm was found, all the rest having passed away. 

Occurrence of the disease. — The worm, though present throughout the 
year, is more abundant in the locality of Washington during May and 
June than at any other season. This fact was doubtless somewhat de- 
pendent on the age of the lambs examined, which were about three or 
four months old at that time. In Colorado an outbreak was heard ol 
in a flock of Merinos which occurred annually about July and August, 
after which time the lambs would improve. The disease is more prev- 
alent in the summer season, and causes the greatest damage in lambs 
less than six months old. If the young animals cm be carried beyond 
this age they seem to be cither better able to withstand the ravages of 
the parasite, or to have reached a season unfavorable for its develop- 
ment. 

Duration. — The broad tape-worms do not last long in theiradult slate, 
but after maturing nearly all their segments are shed at once. From 
the time that the segments are shed the afflicted lambs will begin to 
receive and rapidly lay on fat. The disease leaves no traces other than 
debility in the early stages of recov(;ry. 

Preventive treatment. — Treatment for the prevention of this disease is 
that suggested for general prevention of parasites and an observance 
of those measures which promote good health in the flock. Do not 
overstock pastures. Give good, pure water. When possible, put the 
lambs on new pastures. Feed some grain, put salt where the animals 
can take it daily, feed hay from racks, and grains, salt, and water from 
troughs. 

The medical treatment jiromises better results than that for Tccnia 
fitnhriata, since the T. expansa is never lound wedged into the gall duct 
or pancreatic duct, as is T. Jimbriata, but is found lower down in the 
small intestine, from whence it can be removed. Many of the popular 
tape-worm remedies are said to be efficacious, butas the disease is dif- 
ficult to diagnose until the worms begin to shed their segments much 
damage is done to the health of the lambs before treatujent begins. On 
those farms and ranches where it appears periodically the lambs should 
bo treated as soon as they begin to show symi)toms. Even then com- 
plete cure can not be attained, for the lambs will continue to pick up 
eggs as in the first instance. For safety all sheep in the flock should 
be dosed, especially if all are to occupy the same pastures as those 
afl'ected. 

Zurn {Die Schmarofzer, etc., p. 191, 1882), says that treatment is 
practical when the disease is recognized before the lambs and yearlings 
are reduced to a cachectic coiulition. Although those far reduced in 
strength may not survive a medication, still they should be dosed in 
order that the parasites may be expelled. Otherwise the si(!k not '^reated 
should be yarded by themselves or killed and buried, so that they may 
not scatter eggs for further infection. Before giving the sheep any 



121 

worm remedies they slioiild be prepared by witbboldiiif? food the night 
before and not watered on the morning of treatment. The dose should 
be administered at one time, allowing every animal to swallow it slowly 
if liuids are giv^en. They should not be turned out alter dosing, but 
should be watched during the day to see if the worms are voided. If 
the worms are not passed off the dose should be followed by a cathartic 
on the next day. If it is certain that the sheep have tape- worms and 
none appear, the animals should be redosed with increased quantities 
on the following day. Of course particular attention must be paid to 
the purity of the drug given. 

After the sheep have been driven out the yard should be cleansed by 
removing the surface earth. This dirt should be placed where it can 
not be washed on to the grass to which the sheep have access ; or, it may 
be thoroughly disinfected, burned, or buried. Cleansing the yard may 
save a reinfection. 

Ziirn (o. <i., p. 192) details experiments made by Schwalenberg, in 
which wormseed, Persian insect powder, petroleum, Chabert's oil, ka- 
niala, kousso, and koussin were tried. The last three gave good results. 
In the first experiment 3.75 grams kamala (about 1 dram) were given to 
each lamb. This dose caused diarrhea and removal of the tape-worms 
in forty-eight hours. The lambs remained poor for a long time, in spite 
of good care. 

In the second experiment 7.50 grams kousso (nearly 2 drams) given 
each lamb gave good results. 

Koussin, also known as ta3uiin or brayerin, in 12 centigram or 2grain 
doses, gave better results. The tape- worms wereexpelled. The treated 
animals remained cheerful, retained their api)etites, and improved in 
condition. 

Picric acid, 10 to 20 grains, made with meal and water into a pill, is 
also recommended for lambs. Tbis quantity is sufficient for one dose, 
and should be followed by a cathartic. Epsom salts in 4-ounce doses 
is a good saline cathartic, or 4ounce doses of the bland oils, adminis- 
tered slowly, may be used. 

The powdered male-fern root, in 2-ounce doses, is recommended, or 
the letberic oil of male-fern in dram doses. The latter is the best. It 
can be given in combination with from 2 to 4 ounces of castor oil. Dr. 
H. Piitz {Seuchen und Herde Krmikheiten) recommends dosing in the 
morning, and withholding all food the night before giving the medicine, 
and on the following morning to give a cathartic. This may be unneces- 
sary, however, when the male-fern has been given with castor oil. 

Frobner {Tlnerarztliche Arzneimittellehre, 1889), gives the following 
recipes for lambs with tape-worms: Take of koussin 3 grains, and of 
sugar 10 grains, mix, and give at one dose. The dose of tansy is from 
2 to 6 drams. It forms one of the chief ingredients of Spinola's worm 
cake, which is fed to lambs as a preventive medicine against worms. 
The recipe, sufficient for one hundred sheep, is as follows: Take of 



122 

tansy, cala-nus root, ami tar cacli 2.] iKiiiiids; of cookin.u-salt, 1| pounds; 
mix tiiese with water and meal, make into cakes, and dry. This is an 
old and oft-repeated recii)e, bnt I can not vouch for its efliciency. 

Powdered areca nut may be given to lambs in from 1 to 8 dram doses. 
If it does not produce a stool in three or four hours it should be fol- 
lowed by a cathartic. 

Ground pum[)kin seeds are in repute with some, but it is dillicult to 
induce sheep to eat tiie required dose. 

Ti'Wor {Diseases of Live Stocky 187!), ]). .'')S.']) recommends saltinjj liber- 
ally, and <;iviiig once a week the followin<if saline tonic; and bitter-licic 
as a preventive against worms: Take of common salt 2 pounds, sul- 
phat(5 of magnesia 1 i)Ound, sulphate of iron and powdered gentian, 
each half a pound, and mix with ground feed or fodder sufficient for 
seventy live to one hundred sheep. This re(;ipe is a very satisfactory 
one for impr()\ing llie appetite and health of the sheep, but probably 
can not be depended on for keeping the worms away. 

For tapeworm in sheep the same author recommends: Powdered 
areca nut, one-half to 1 dram ; oil of male-fern, 10 to 20 drops: give in 
mohisses and water, and follow the next day with a i)urge. For purges 
he gives two recipes: Sulphate of magnesia, 2 ounces ; warmwater, I 
pini in one drench; or, castor oil, 3 ounces; calomel, 12 grains; mo- 
lasses, 3 ounces — for one dose. 

After the sick lambs have been treated, care and attention should 
not be relaxed, for it is of the utmost importance that the^' regain their 
strength and vigor before the cold weather sets in. The best pasture, 
an extra feeding of hay, and some roots and grain in judicious (luanti- 
ties, should be allowe<l them. The feeblest should be kept by them- 
selves, where they can get plenty of food and water without entering 
into comiietitioii with the stronger. This treatment should be kept up 
until they are fully able to hold their own. 



124 



TAENIA EXP ANSA, Riul. 

Plate XIV. 

Figs. 1 aud 2. Young tape-worms, natural size. 

Fig. .3. Head end of tape-worm, drawn to show vermieular eontractions when living. 

Fig. 4. Head, top view : a, a, the suckera or cups, by which the worm attaches 

itself to the intestinal walls. 
Fig. 5. Head, side view : a, a, suckers ; h, h, folds in the neck ; c, c, the first segments. 
Fig. 6. The large end of a young tape-worm : o, a, segments which are not mature 

enough to drop off; b, J), segments ready to pass away from the worm. 
Fig. 7. Segments, or proglottides found, se})arate from the worm. 
Fig. 8. An adult tape-worm, drawn in sections at regular intervals apart: a, head. 
Fig. 9. A fragment of another worm, which is not only slightly larger, but whose 

segments are shorter and broader. 
The specimen shown in tig. 8 could have assumed very much the same form when 
alive as is seen in fig. 9. 



PLSTE XIV 



^ 










11 



i— — ^ 




-3 



s^ - 






F:^ 



«. r 




la 



g^ 






i 



^ 



r' 



=i3 



Geo. Marx, dd. 



^'^<::£::^- 



TAENIA EXPANSA, 
(The Broad Tape-Worm.) 



12G 



T.ENIA EXl'ANSA EMUKYOS. 

Tlatk XV. 

Fig. 1. Embryos iiiasiiificil and llattoiuul uiuler covoi-glasa. 

Fig. 2. A single onibryo and its unveiov)es sonunvhat llattencd. 

Fig. i{. Tlie sanio greatly tlattened : a, the thick, oily mass between the inner and 

onter covering, 
Fig. 4. The same with outer envelope ruptured: «, the outer envelope; h, the in- 
ner; c, oil globules; d, the embryo and its pyritorm apparatus. 
Fig. 5. Embryo, with three envelopes. 
Fig. 6. Embryo escaped from ruptured inner coat: «, the fringed cap-like covering; 

/), the bladder-like sac protuding from it; c, the six-hooked embryo. 
Fi"-. 7. A younger embryo, inwhich the bladder portion has not burst from the capj 

a, the cap ; b, the embryo. 
Fig. 8. Three young tiv.nia which show no trace of segmentation. 
Fig. 9. A young Imiia which is beginning to segment. 
Fig. 10. A head of young speciineu showing a peculiar loop in it. 



PL.HTE XV 



\J 








Geo. Marx, del. 



TAENIA EXPANSA 
(Young Stages.) 



THE LIVER FLUKE-LIVER-ROT. 

DiSrOMA HEPATICUM, Liuii. 
Plato XVI. 

The liver tluke disease, wliicli causes so much loss in Great Brit- 
ain and on the European continent, is comparatively unknown in this 
country; so rarely, indeed, is it discovered that most authorities on the 
management and care of sheep seem never to have seen it. That it 
has occurred in this country, and that it is present iu certain portions 
of it, is tolerably certain, for good observers have recorded it at various 
times. 

Henry Stewart, in the tihcpherd'ii Manual^ 1882, page 223, says that 
flukes were found in a flock of Southdowns at IJabylon, Long Island, 
and also in Cotswold, Leicester, and native sheej), presumably at the 
same place. In the Tenth Cerisus Reports of the United States, Yo\. Ill, 
flukes are said to occur in Texas and California. In the latter State 
they have been seen by Prof. E. C. Stearues, of the Smilhsouian Insti- 
tution. 

The disease occurs so infrequently iu this country that the writer has 
seen but two cases of it, and both of these were iu cattle. For a de 
scription of the nuilady we will therefore have to depend upon writers 
iu those countries where it occurs more frequently thau it does here. 

Description. — Body fljitteued, leaf-like, pale brown, irregular, the adult from 18 
to 31""" long, from 4 to 13""" wide, oblong, oval or lanceolate, larger and rounder iu 
front, where it is abruptly contracted in such a way as to present a conical neck; 
attenuate and obtuse behind. Skin bristling with numerous little points directed 
backward. Oral sucker terminal, rounded. Ventral sucker large, projecting, with a 
triangular opening situated about 3""" behind the lirst. Intestine with two rami- 
fied branches visible through the skin and of a deep shade. Penis projecting iu 
front of the abdominal sucker, always recurved. Vulva very small, situated at the 
side of the male orifice or a little behind. Eggs brown or greenish, ovoid; length 
from 0.130 to 0.14.5""" ; width from 0.070 to 0.090""". (Neumann.) 

Occurrence. — This parasite has been found in the livers of sheep, 
goats, cattle, camels, and certain wild ruminants. It has also been 
found in the horse, ass, pig, elephant, rabbit, and man. It lives in the 
biliary ducts of the liver, and, according to Kiichenmeister, feeds on 
blood drawn from the mucous membranes of those passages. The par- 
asite does not appear to be equally abundant at all times in Europe, 
but seems to develop at various periods in sufficient numbers to cause 
epizootics. A number of these outbreaks, compiled by ISTeumann, o. c, p. 

1:^7 



128 

463, demoustrate no periodicity or law by which future outbreaks may 
be susi)ected or i)redicted. 

Sheep-owners and veterinarians are agreed that damp, wet seasons, 
and damp pastures are favoring conditions for the development of the 
parasite an<l proinotiou of the disease. 

The life history of the parasite has been determined by Leucliurt in 
Germany, and a little later, but apparently independently, by A. P. 
Thomas, in Enjiland. The former published his observations in Zoolo- 
(jiachcr AnzeUjer, December 12, 1881, and October 9, 188'J, and the lat- 
ter in the Journal of the Royal Agricultural Society of Umjland, Vol. 
XVIII, part 2, 1882, and Vol. XIX, parts 1 and 2, 1883. These authors 
have described most of the stages in the life history of the parasite, 
leaving but little to be said in addition. 

The i^gg of the tluke passes from the biliary passages through the in- 
testine to the ground (Plate XVI, Fig. 2a). Those that fall in ftivorable 
places develop (Fig. 2b) and finally break the little lid oif the eiul of 
the shell (Fig. 2c) and escape. This happens in summer and occupies 
from three to six weeks. At this stage (Fig. 3) the whole body is covered 
with fine cilia (hairs), which enable the embryo to swim about in the 
water. At one end of the embryo is a little projection which can be 
thrust out and withdrawn, and is the apparatus by which it bores into 
its second host. If it does not meet one in a day or two it dies. If it 
meets a water snail (Fig. C and C«), it is not slow to penetrate into the 
body, where, according to Leuckart, it lodges in the respiratory cavity. 
Here it encysts itself (Fig. 4), contracts into an oval mass, and rapidly 
grows. The name sporocyst has been applied to this form. The con- 
tents of this sporocyst split up into a number of bodies (Fig. 4), usually 
from five to eight, which develop into rediw (Fig. 7). Their length 
at this stage is about 2""", or one twelfth of an inch. These are ex- 
cluded from the sac one by one through a rent. Now each redia, in 
its turn, develops from fifteen to twenty cercaria' (Fig. 8) within it, which 
are evacuated in turn through an unpaired orifice situated under the 
neck of the redia. The cercaria> are the forms that escape from the 
snail, and are scattered by it in its wanderings. The cercaria, after a 
time of active life, loses its tail, which it has developed, and again en- 
cysts itself. (vSee Figs. 11 and 12 and Fig. 10.) The contents of the 
cyst still more resemble the future fluke, and it is at this stage that 
the sheep swallows it with grass. It then breaks from the cyst, arrives 
at thti stomach and duodenum, to finally make its way into the biliary 
canals and grow into another, adult hermaphrodite, capable of giving 
rise to other generations of young. 

According to Thomas the en'eysted embryo (Fig. 4) may give rise to 
daughter redi;e or to cercariiB, the former to develop in the summer and 
the latter during the cold season, 

The epitomized life history is first the egg ; second, the embryo^ which 
encysts in a snail j third, five te eig^t redise, developing from the cystic. 



129 

larva ; fouitli, fifteeu to twenty cercariiB, developiiij^- tioin each redia 
aud escapiug from the snail; tiftb, the encysted cercari;e, which after 
having been swallowed by a lamb develop into adult Hiikes. 

This life history is fully as wonderful as any occnring in nature. Ac. 
cording to it, at least seventy-live young flukes under favorable sur- 
roundings could develop from a single egg. As the proper conditions 
are scarcely ever fulfilled, there are but few of those which meet with 
all the requirements for development. 

The disease created by these peculiar parasites is known by many 
names, the most popular of which is Liver Rot, a term expressive of the 
chief pathologic symptom. Aqueous Cachexia, Rot, Rot Dropsy, Sheep- 
Rot, Liver-Disease, Liver Fluke, Jaundice, Yellows, Verminous Phthisis 
of the Liver and Ictero-Verminous Cachexia, are other names for the 
disease, each being expressive of some of its symptoms. 

The symptoms, according to Neumann (Maladies Parasitaires), to whom 
the writer is indebted for the greater part of this article, may be divided 
into four periods, viz : 

(1) Period of immigration.— This is the period in which the parasite 
invades the liver. In this stage the flukes are small aud do not cause 
excessive diisturbances. This period lasts from four to thirteen weeks. 
It is probable tUat it lasts as long as the weather remains fiivorable 
for the development of young flukes aud sheep are kept on infested 
pastures. 

(2) Period of anwmia.— This ordinarily coincides with the months of 
November ami January, or after the lapse of thirteen weeks from infec- 
tion. The sheep are less lively ; the mucous membranes about the eyes, 
the nose, and the gums, the internal surface of the ears aud the skin, are 
all paler than in well sheep. The appetite is still good, aud the animals 
have a teuden(;y to fatten, caused, according to Simouds, by a better 
assimilation of food from the increased flow of bile stimulated by the 
young flukes. This fattening stage has been taken advantage of in 

■ England by a dealer (Bake well), who purposely exposed the lambs he 
wished to market early to the disease, that he might send fat lambs into 
the market five or six weeks ahead of his neighbors. Sometimes the 
appetite diminishes, thirst increases, and rumination is irregular. The 
conjunctiva, the mucous membranes of nose and mouth, and the skin 
are white, slightly tinged with yellow. There is a slight oodema (puf- 
finess); the skin is looser, feels pasty and soft to the touch where bare; 
the conjunctiva is infiltrated atul puffy and the eye partially closed ; 
the wool becomes dry and brittle, is easdy pufted oft", and sometimes 
falls ott" of itself. Weakness appears more and more marked. There 
is sometimes fever aiul quickened breathing. Palpation and percussion 
indicate ascites. The droppings are norm:d, but contain at the end of 
this period numerous fluke eggs, Death may result iu this stage from 
apoplexy. 

23038 A p 9 



130 

(3) Period of loss of flesh. — The sheep begin to become leaner at the 
end of the third month after the immigration of the hirvae, or about 
the beginning of January. The malady is then at its height. The 
animal becomes gradually leaner; the mucous membranes and the skin 
are bleached, and lose the yellow tinge. The temperature is variable 
and is highest in either the morning or evening. Kespiration is feeble 
and frequent. The appetite keeps up, and the feces present nothing 
in particular except fluke eggs. The urine is nearly normal. The ani- 
mals are listless and dejected, carry their heads low, and give way when 
pressed on their backs. There are frequent abortions, isursing ewes 
have a clear, watery milk, very poor in nutritive elements. Their lambs 
are weak and thin, and usually die unless they are put to another nurse. 
The oedema becomes localized and increased in dependent parts. It is 
dispelled by walking and comes again in rest. The space under the 
jaws and along the trachea is a frequent seat of pufSness. This disap- 
pears during rest and comes on during feeding. It is often absent 
with adults in hot seasons. In the tliree weeks which follow the ani- 
mals become still poorer despite abundant feeding, and there is gener 
ally diarrhea, oedema, jaundice, and pain on pressure over the liver. 
Either death occurs at this period, or the animals imi^rove and enter the 
next period. 

(4) Period of emigration of theflnl-es. — This is the period of convales- 
cence and of spontaneous cure. All the symptoms grow less and finally 
disappear, but the cure is never complete, the changes which have taken 
place being irreparable. The recovery of affected sheep is exceptional. 

Duration of disease. — The flukes are said by some authors to remain 
nine months in the liver, by others fifteen months. After this time they 
make their way into the intestine and are evacuated with the excre- 
ments. 

Thomas says that he has seen the sickness last six years, and Neu- 
mann seems to coincide with Perronciro, that the flukes have little ten- 
dency to quit their hosts. The question of reinfection of the same ani- 
mal would leave it doubtful whether such long period of infection were 
all due to the same parasites or to renewed generations of them. 

The duration of the disease, which, as a rule, is variable, depends en- 
tirely on the degree of infection and the treatment, hygienic and me- 
dicinal, which they receive. It ordinarily lasts about six mouths, but 
excei)tionally may have an extremely rapid course of a few days, death 
being caused by an acute iuttainmatiou of the liver, set up by the para- 
sites, and occurring in from seven to nine days after the first appear- 
ance of the disease. Weakened by the fluke disease, the animals are 
more susceptible to other maladies, and these may destroy them before 
the primary disease has run its course. 

Diagnosis. — There is little difficulty in diagnosing liver-rot in the 
stages at which it is first noticed if the flock-master sacrifices one of the 
worst affected sheep. Although he may think that it hardly pays to 



131 

kill a sheep to find out what the trouble is, he will subsequently learn 
that, a little loss in the beginning leads to a great saving in theend, and 
therefore becomes an investment. 

In fluke disease not one or two lambs only are infected, but all the 
flock that have been feeding together. If the flock-master has a micro- 
scope he cau detect eggs of the fluke in the droppings, but this can only 
be found after the fluke has matured and the disease has well advanced. 
Besides, it requires some skill to make the required examination. So 
numerous are the eggs and so characteristic is the shell with its little 
cap, however, that this method forms an important element in diagno- 
sis. The droppings should be moistened with water and thoroughly 
picked to pieces, then spread evenly on a piece of glass and covered by 
another thin glass. The mass should be closely examined with the aid 
of a microscope magnifying from 70 to 80 diameters. This operation 
should be repeated a number of times if eggs are not found. The ex- 
amination of the liver is tlie best means of diagnosis. When the gall 
ducts are cut open the young flukes will be found in them. They usu- 
ally occur in smaller or larger nodular swellings. The structure of the 
liver is also characteristic, presenting a dark, soft, rotten ai)pearauce. 
Young flukes can be found by cutting into this organ and washing it in 
water. After allowing everything to settle, pour oil" the top and repeat 
the operation until the contents of the dish can be distinguislied. When 
spread out on aflat-bottouv ddish the flukes may be easily distinguished 
by the unaided eye, or, if very young, by tlie help of a small lens. If 
the sheep has been killed the flukes will be iseen to wriggle and curl, 
for they die slowly in water ordinarily warm. 

Pi-ofjnosk. — The disease is very tenacious, and when once on a farm 
is difficult to extirpate. Many farms in infected localities are rendered 
useless for sheep raising by these parasites. When a flock becomes 
infected it is uot to be expected that the disease will be stopped until 
it has caused extensive damage, and that only the most prompt anil 
effective measures will save any of the afllicted animals. 

Pathology.— Tha disease is seated in the liver, and all the symptoms 
and changes observed in other parts are directly dependent on those 
occurring in this most important organ. The different periods into 
which the various alterations have been divided are directly dependent 
on the [)eriods in the life history of the flukes. For our present purpose, 
however, it seems advisable to give but the most brief description of 
these pathologic changes. 

When the flukes first invade the liver they cause au inflammation, 
which is shown by a thickening of its mass. It becomes softer, and 
the surface, which should be smooth and glistening, becomes rough. 
These changes increase as the days go by, and the liver becomes softer 
and thicker. The surface becomes covered by thready fibers, as well 
as much rougher; the abdomen contains more or less dark-colored 
serous fluid; young flukes from one-tenth to one-fifth of au inch long 



132 

can either be found in serum-filled cavities of tbe liver or attached to 
the outside, or perhaps free in the cavity. Still later, the liver shows 
I^laces i)uckered up, which are caused by the reparative i)rocess and the 
contraction of the newly-formed tissue. There will be numerous chan- 
nels beneath the serous membrane visible to the unaided eye. The bil- 
iary canals will be found thickened and enlarged at places to the size 
of a hazel-nut, or even larger. In these dilatations are flukes of con- 
siderable size, surrounded by a greenish black, sticky mass. Some- 
times hard limy fragments are found in them. The substance of the 
liver becomes very rotten, and crackles under pressure by the finger. 
When the flukes migrate healing takes place to some degree, but tlie 
liver will never look healthy. It will grow considerably smaller and 
become much whiter, due to the connective tissue changes which take 
place. 

Preventive treatment, — Thomas has formulated rules of prevention 
against this parasite, which are founded on its life history and seesu to 
be eminently practical. He says : 

(1) All eggs of the liver fluke must be rigorously destroyed. Mauure of rotten 
sheep or other infected animals must not be put on wet ground. As the liver and 
intestines contain eggs, these, too, must be destroyed or put in the compost heap. 
The manure of affected aniuuils should not be stored where there is a drainage from it 
to the neighboring grass. It should be mixed with lime and salt before being spread 
on meadows or cultivated fields. 

(2.) If sheep are infected, let them be sent to the butcher at once, unless they are 
specinlly valuable and are not badly aflected. If kept, they must not be put onto 
wet ground. 

The above advice is preferable with all common stock; and the ex- 
ceptions, when medicine should be tried, are very few. Stock should 
be very valuable to repay the expense of care and treatment in face of 
the large percentage of death which occurs in this disease, and the ill 
condition of the remnant after recovery. 

(3.) Care must be taken to avoid introducing eggs of the fluke either with manure 
or fluked sheep, or in any other way. Rabbits and hares must not be allowed to in- 
troduce the eggs. 

The most prolific source of introducing parasites is in the introduc 
tion of infected sheep, and purchas<5rs should learn all thej" can of the 
history of the animals they buy, and not purchase from diseased flocks. 

(4.) All heavy and wet ground must be thoroughly drained. 

Draining is of advantage in many ways. It makes tillable land of 
what was before useless, either for pasturage (as shown by its infecting 
the flocks with a fatal disease) or for cultivation. 

(5.) Dressings of lime and salt (or both) should be spread over the ground at the 
proper season to destroy the embryos, the cysts of the fluke, and also the snail which 
acts as host. 

After draining, such fields should be cultivated and suitable crops 
raised on them. 

(6.) Sheej) must not be allowed to graze closely, for the more closely they graze the 
more fluke-germs will they pick up. 



133 

This rule is advisable wherever the sheep may pasture. Sheep on 
over-stocked pastures do not get enough grass, and become more in- 
fested with worms from having to eat close to the dirt. 

(7.) When sheep are allowed to graze ou daugerous grouud they should have a daily- 
allowance of salt and a little dry food. 

Exigencies can be conceived in which sheep may be allowed to pas- 
ture on infected ground, but, in view of the fatality attending the 
malady, it would seem more profitable to sell the animals while they are 
still in good condition than to expose them further to these parasites. 

Lime and salt are the two cheap i)reveutives against this parasite. 
The former, mixed with manure, increases its value as a fertilizer. A 
solution of three fourths of 1 per cent, of salt in water has been found 
by experiments in the laboratory to kill fluke embryos. This weak so- 
lution might prove too weak in tlie field, when the salt would be still 
further diluted by dew or rain. Perroncito has shown that the encysted 
cercaria) and the larvae encysted in Limncva palnsfris die in 2 per cent, 
salt solutions in five minutes; in 1 per cent, solutions they die after 
twenty or thirty-five minutes; 0.05 i)er cent, solutions kill in about the 
same time; in 0,25 per cent, solutions the worms live after twenty 
hours' immersion. 

The weakness of the brine necessary to kill the parasites in the labo- 
ratory points out that a snmll proportion of salt mixed with the lime 
would be very advisable. Salt was first advised from a knowledge of 
the fact that sheep never became infected with flukes on salt marshes. 
Stronger solutions of salt also kill the snails, which are the hosts of the 
embryonic fluke. 

The time of year for scattering the lime or salt on the fields is the 
first part of June, July^ and August. 

Neumann advises mixing two teaspoonfuls of salt for each sheep 
with the ground grain they eat. Perroncito advises the addition of 
one-half of 1 per cent, salt to the water they drink (about a heaping 
tablespoonful to each gallon of water). 

Although the flockmaster can never completely cure his sheep, he 
may, by judicious medication, so improve the condition of the con- 
valescent animals that they will take on considerable flesh. Many 
vegetable astringents and tonics have been tried, with more or less 
profit, but it is to the mineral astringents that we look for the best re- 
sults. Sulphate of iron and common salt, dissolved in the drink or 
mixed with the food, are among the best and cheaj)est. 

Medicinal treatment. — Some experimenters have endeavored to kill 
the flukes, and have met with varying success. The remedies tried 
have been extract of male-fern, given with turpentine or benzine, castor 
oil, etc. For proportions of these remedies see remedies for Twnia ex- 
pansa. Mojkowski, according to Neumann, has obtained encouraging 
results against the distomatosis (the fluke disease) of sheep with naph< 



134 

tlialiiie, given twice a day during a week, in from 10 to 15 grain doses, 
alone, orniixed with i)owdered gentian. 

The following recipes, to be used as licks, may be useful in small 
flocks : 

Take of sulphate of iron, 2 ounces ; calamus root, 1 pound ; of crushed 
oats and roasted barley malt, of each, 20 quarts. This quantity is 
sufllcient for one hundred sheep. Other mixed grain may be substi- 
tuted for the barley-malt and oats. Or, sulphate of iron, 1 ounce, and 
powdered juniper berries and gentian root, of each, 1 pound. Mix 
with 20 quarts of grits. A lick for fifty sheep. 

A very complicated but apparently good tonic remedy is known as 
Spinola's worm-cake, see page 121. Vieth recommends the following: 
Oak bark, calamus, gentian root, and juniper berries, of each 2 pounds. 
Pulverize and add pulverized sulphate of iron, 1 pound; pulverized cook- 
ing-salt, 10 pounds. Mix thoroughly, and give each sheep a teaspoonful 
every two or three days. The medicine is most easily administered 
mixed with meal, chops, bran, etc. Either of the vegetable ingredients 
of the above recipes can be omitted and substituted by some other well- 
known tonics, though each is thought to have its special virtues. The 
dietary treatment is the most valuable. Grain-feeding, mashes, strong 
meals, as flax seed meal cakes, or cotton-seed oil cakes, can be given in 
judicious quantities. The general treatment should embrace every 
means known to the flock-master to sustain the health of the flock. 

Police sanitation. — The meat of slieep aftected with liver-rot is safe to 
eat, but in advanced stages of the disease it is too watery, lean, and in- 
nutritious to be wholesome food, and is only an inferior article. When 
killed during the early stages of the disease it is more salable ami nutri- 
tious. Later on, it should not be put on the market or received by 
buyers. 



13G 



DISTOMA HEPATIC UM, Liun. 

Plate XVI. 

Fijif. 1. Adult fluke, luatiiral size : la, young fluke, natural size, (Raillet.) 

Fig. 2. Eggs: a, egg with developing emWryo; b, egg with embryo; c, egg-shell. 
(Raillet.) 

Fig. :?. Ciliated and free embryo : «, perforating apparatus ;/>, ocular spot. (Leuck- 
art. ) 

Fig. 4. Encysted embryo found in suails. (A.P.Thomas.) 

Fig. 5. Diagram of digestive apparatus and nervous system : a, mouth sucker; b, 
pharynx; c, oesophagus; d, branches of intestine ; e, their brauchlets ; 
/, nerve ganglia ; g, ventral nerve. (Raillet.) 

Fig. 6. Limnrvns trimcatuluft, the principal snail which is the larval host of the fluke 
in Europe: a, natural size. (Raillet.) 

Fig. 7. Redia of ]>i8toma hcpadeum : a, mouth; h, pharynx; c, digestive tube; d, 
the so-called germinative cells destined to produce cercaria'. (Leucdiart.) 

Fig. 8. Redia coutaiuing cercari;e: o, mouth ; />, pharynx; c, digestive tube; d, d, 
cercaria^ (Leuckart.) 

Fig. 9. Cercaria dissected from its cyst: a, anterior sucker; ft, ventral sucker ; c, 
pharynx ; d d, branches of the intestine terminating in cieca. (Leuckart.) 

Fig. 10. Grass stalk with three encysted young flukes, a, a. (A. P. Thomas.) 

Fig. 11. Free-swimming cercaria just before it is about to encyst. (A. P. Thomas.) 

Fig. 12. A slightly older stage than Fig. 11. (A. P. Thomas.) 

Fig. 13. Genital apparatus of the liver fluke : a, digestive tube ; b, ventral sucker ; 
c, anterior testicle; d, its deferent canal ; e, posterior testicle; /, its def- 
erent canal; g, seminal veside ; /(, genital sinus; i, cirrhus pouch; /, 
ovary; A, oviduct; /, shell-gland; m, yolk glands; «, longitudinal and 
0, transverse yolk-glaud canals ; p, uterus; g, vagina. (Raillet.) 



U" :xt^ 



10 



21 




3t4 











Haines, del. 





DISTONIA HEPATICUM 
(The Liver Fluke.) 



137 



DISTOMA LANOEOLATUM, Meblis. 

Plate XVII, Figs. 11 to 15. 

Description. — Body semi-transpareut, spotted with brown by the eggs, length from 
4 to 9'"'", width 2.5""", lji,nceolate, obtuse behind, attenuate forward, and terminated 
by the oral sucker, which is nearly as large as the ventral. Integnment smooth, 
intestine with two branches, not further subdivided. Penis long, generally straight. 
Genital orifices very close to one another. Eggs ovoid, length from 0.037 to 0.040'"'". 
(Neumann.) 

The life history of this parasite seems to be as yet unknown, but it is 
believed to be analogous to that of Disfoma hepaficum. The embryo 
(Fig. 11) differs from that of D. hepafieum in being globular, armed with 
a cephalic spur, and in being ciliated only over the anterior third of the 
body. Its movements are said to be slower. 

Ercolani has shown that young embryos measuring 1'"™ first show 
traces of a digestive system (Fig. 14), and that the digestive system is 
preceded by groupings of cells, which first outline the testicles, then the 
penis, and lastly the ovaries. Two species of suails, Planorbis margi- 
nntns and Helix carthusina, which contained cercarire, have been pointed 
out, the former by WillemoesSuhm and the latter by Plana as the in- 
termediary hosts of the fluke. 

This species of fluke never produces symptoms or lesions as gra^e as D. hepnticum, 
and can only occasion aqueous cachexia or dropsy. This relative harmlessness is at- 
tributed by Leuckart to its small size and the absence of spines on the skiu. The two 
species are most often found together in the same host. By reason of its minute size, 
D. lanceolatum penetrates into the finest biliary cajials, where the young D. hepaiicum 
can not enter. Because the individuals of the former species escape observation on 
account of their small size they appear to be fewer in number. Friedberger has ex- 
tracted some thousands from the biliary passages by squeezing the liver. They are 
also found in great numbers in the gall bladder and in the intestine at the time of 
their emigration. (Neumann.) 

The means of prevention and treatment are the same for this as for 
Distoma hepaticum. Treatment is of more avail. 



PARASITES OF THE RUMEN. 
Amphistoma conicum, Zeder. 

Plate XVII, Figs. 7 to 10. 

Body of a rose tiut, irregular, and more or less dark. It is ovoid, narrowed in front^ 
and swells gradnally even to the posterior end; obtnse and slightly recurved on the 
ventral fiice. Length from 10 to 13""", width behind from 2 to 'A"'"'. (Nenmann.) 

This parasite has been found in sheep in India au(i Australia. The 
author has not observed it in this country. It oc3nrs scattered amongst 
the large villi of the rumen or first stomach, attached by its posterior 
sucker. It is said to cause but little digestive disturbance. Figures 
and description of this parasite are presented, as it is a representative 
of the genus, and may sometime serv^e for generic determination of 
allied parasites which may be found in this country. 
138 • 



140 



LINGUATULA T^NIOIDES, Eiulolpbi. 

Platk XVII. 

Fig. 1. Male, natural size. (Cobbold.) 

Fig. 2. Female, natural size. (Cobbold.) 

Fig. 15. Egg with contained embryo. (Lenckart. ) 

Fig. 4. Embryo escjiped from egg-shell. (Lenckart.) 

Fig. 5. Pupa nine weeks old: «, anus ; fc, mouth. (Leuckart.) 

Fig. 6. Llngnatula deniU'ulatitm. (Leuckart.) 

AMPHISTOMA CONICUM, Rudolphi. 

Fig. 7. Piece of the rumen of a cow, showing the parasite attached between the 
papilla? by their large posterior sucker: a, au isolated individual, natural 
size. (Raillet.) 

Fig. 8. Dorsal view, X'2. ^Blauchard.) 

Fig. 9. Lateral view, X2. (Hlauchard.) 

Fig. 10. Egg of an amphistoma, XHO. (Cobbold.) 

DI8T0MA LANCEOLATUM, Mehlis. 

Fig. 11. Ciliated embryo. (Leuckart.) 

Fig. 12. Early stage of development, in which there is no digestive apparatus. 
(Ercolaui.) 

Fig. 13. Another stage : a, a, groups of cells representing the future testicles. (Erco- 
laui.) 

Fig. 14. Stage showing the testicles plainer, a, a ; h, the rudimentary cirrhus pouch, 
and c, the digestive system. (Ercolaui.) 

Fig. 15. Adult, natural size figure by its side: a, pharynx; />, o'sophagus; c, branches 
of iutestine ; d, ventral suckers ; e, e, testicles ; /,/, deferent canals ; g, cir- 
rhus pouch ; h, ovary; i, albuminous glands; k, uterus; I, vagina. 



PLKTE XYII 




Haines, del. 



LtNGdATHLA TAEXIOIDES. 



AMPHISTOMA CONICUM. 



DISTOMA LANOROLATUM. 



THE STOMACH ROUND WORMS. 

Strongylus CONTORTUS, Illld. 
Plate XVIII. 

Strongylm confortus, or the twisted strong.yle, is an inhabitant of the 
fourth stomach of sheep and goats. Though in the majority of flocks 
it produces but little if any disturbance, yet there are times when, in 
connection with other species, it causes disease which may carry otf 
numbers of lambs. In the southwestern States and Territories the 
disease has been called lombriz, a corruption of the Spanish word lombrici, 
meaning- worms. The later writers seem to be inclined to attach a 
si)ecific meaniug to this word, while the Mexicans, who used it, merely 
intended to say that the lambs died of worm disease. 

Description. — Female, 18 to :iO'"'" loug; male, 15 to *20'"'" long; body reddish; 
female luarked by a double spiral white line, thicker toward the caudal end. The 
«kiu shows eighteen lougitudinal Hues. The mouth is louud aud without visible lips 
or papilhe. The ueck has two barb-like side papilke; uuicellular glands scarcely 
visible. The male is about two-thirds as long as the adult female, and shows no 
spiral Hue. Bursa deeply bilobed, with a small dorsal lobe attached to one of the 
pair. The lobes are somewhat longer than broad. The ventral cost;ie are separated ; 
the lateral are double and separated ; the dorso-lateral is attached to the lateral group 
near its base; the dor-sal cost;o support the dorsal lobe and each branch is doable; 
the twofold character is indicated by a little notch. The lateral costiB are irregu- 
larly divided, many variations being observed. Spicula two, embracing a chitinous 
piece between them. They are short, cyliudrical, barbed on one side near the end, 
and have blunt tips. Female: Vnlva 3""" from the tail and covered by a nipple- 
like projection, 0.5'"™ long; the latter has thin borders, and is concavo-convex, to fit 
the body when pressed against it.. Uteri two, each opeuinginto the common vagina ; 
one is anteriorly directed and the other posteriorly, with a short loop between it and 
the vagina. The ovary of the posterior uterus is reflected anteriorly to rejoin its fel- 
low, and together they wind spirally around the dark-colored intestine. The ovoid 
eggs are laid in the gastrula form, or after they have passed through the segmenta- 
tion stage; length, 0.070 to 0.097"""; width, 0.043 to 0.054'°™. 

Occurrence. — This worm may be found in all stages in the fourth 
stomach or abomasum of sheep. When collected immediately' after 
death from a slaughtered sheep they may be detected adhering by their 
heads to the mucous membrane. They are then of a reddish color, which 
may be because they feed in part upon the blood of the victim. 

Tlie life history of Strongylus contorlus seems to be apparently simple. 
Among a number of lambs kept at the Experimental Station in 18S8 
were two or three which had been raised thei-e. A post-mortem exami- 

141 



142 

nation of one of these, with four other lambs which had been at the 
Station for the five previous mouths, revealed numbers of IStroiujylns 
eontortufi in all stages of growth, and of Dochmlus ccrnuus, Trichoceph- 
alns affinia and Tcenia expansa. These lambs were sup[)lied with well wa- 
t«"r, and were allowed to run iu a small, dry, grassy yard connected with 
a stable. The presence of these species of all sizes iu the former group 
of lambs showed that they acquired them on the place, and that their 
development was direct; that is, they did not pass through a secondary 
host in passing between the sheep and thelambs, for all of the conditions 
were uuder inspection. The grass iu the 3 ard became very short, and 
probably it was because the sheep ate it so close to t he ground that they 
became more infested with worms than sheep ordinarily do. The his- 
tory, therefore, is probably as follows : The eggs fall to the ground ; 
they are eaten by other sheep along with their feed, and they then ar- 
rive at the stomach and develop there. 

The disease they cause can not easily be distinguished from that pro- 
duced by other iutestinal parasites. In the worst cases, besides a gen- 
eral lack of tone aud good health, there is weakness, paleness, some 
fever, diarrhea, etc. In fatal cases death is said to occur within a very 
few days after the illness is observed ; but, as the parasites develop 
slowly, it is probable that no symptoms of illness are apparent until 
after the lambs have been ailing for some time. A positive diaguofeis 
is to be made only by i\, post-mortem examination. The little worms, if 
[)resent iu large numbers, will appear like masses of threads lying iu 
the stomach. If the sheep has been killed for examination, the worms 
will be seen wriggling and squirming in all directions. 

Treatment. — Various remedies are proposed, but of those available 
an emulsion of milk and tur[)eutiue, prepared by shaking the mass well, 
seems most practicable. Add 1 part of spirits of turpentine to 16 parts 
of milk, and give from 2 to 1 ounces of it to each animal, according to age 
of patient. Oue dose should be sufficient ; if not, repeat it in three or 
four days. Or, take of linseed oil, 1 ounce; turpentine, one-half ounce, 
shake well and give Jis one dose. Quantifies sufficieut for any number 
of sheep may be made upiu these proportions. 

The following recii)e is from Finlay Dun's Veterinary Medicine: 
Common salt, 3 pounds ; powdered ginger and niter, half a pound each ; 
dissolved iu 3 gallons of warm water ; add 21 ounces of turpentine 
when nearly cold. The dose for iambs between four and six months' 
old is 2 ounces. The entire quantity is sufficieut for one hundred and sixty 
lambs. For delicate landis, which are coughing and i»urging, the same 
writer recommends oil of turpentine, i)owdered gentian, and laudanum, 
2 ounces each, all to be dissolved and stirred in 1 quart of linseed tea 
or lime water. This quantity is sufficient for ten or twelve doses. 

Ziirn recommends (after Rabe) the picrate of potash, because it is 
less irritating to the [)atients. The dose ior a lamb is from 2.^ to 5 
grains; for an adult up to 20 graius. It can be given dissolved in 
water. 



143 

Dr. H. J. Detiners, in a report to the Commissioner of Agriculture, 
1883,- on the diseases of slieep in Texas, fecommenils the use of tartar 
emetic as follows : A half pound of tartar emetic is to be dissolved iu 
12 quarts of water, and from 1 to 2 ounces of the solution, containing 
from 5 to 10 grains of the remedy, is to be given each patient, depend- 
ing on its size. He recommends dosing out of a small 2-ounce vial, 
and in small swallows. 

Good, nourishing food, and a dry yard in summer, or a healthy, well- 
ventilated stable in fall and winter, are advisable. In giving medicine, 
drench from a horn, a spoon, or a stout glass bottle. Bottles are always 
liable to break. Let an assistant throw the sheep onto its haunches 
and hold it between his legs, back toward him. With the lower jaw 
seized in his left hand, from the left side, he can either seize the upper 
jaw or pull out the cheek-pouch with his right. The medicines are 
best administered while the sheep are thirsty. Small doses va-dy be 
diluted, but a dose of 4 or 6 ounces is more apt to run directly into the 
fourth stomach than larger doses ; otherwise, some of the latter might 
be diverted into the second stomach and fail of an immediate effect. 

The following recipe was recommended to the readers of Field and 
Farm, August 7, 1889, as a preventive remedy for worms in sheep. Mr. 
G. B. Both well, of Breckenridge, Mo,, who used it for fifteen years with 
success, is its author. 

Salt, 1 bushel ; air-slaked liuie, 1 peck ; sulphur, 1 gallon ; pulverized rosin, 2 <|uarts ; 
put iu trough with cover, where sheep can have free access. When sheep become 
thoroughly infested witii worms death is almost sure to follow, but the above, if 
kept before the sheep, will surely act as a preventive. 

A more complicated arsenical recipe for worms, the source of which 
is unknown, is as follows: 

Take of arsenic, washing soda, and carbonate of soda, each 1 ounce; 
put them into 2 quarts of hot water; boil, and stir for one-half hour, 
then add 10 quarts of cold water. The dose for a lamb, after weaning, 
is one-third of a gill. If the lamb is not very sick give but one dose, 
but if badly affected repeat iu nine days. 



144 



STRONGYLUS CONTORTUS, Rud. 

Plate XVIII. 

Fig. 1. Adult feraalo, X6: a, bead; b, ovaries wound arouud tlie intestines; c, c, 
uteri; d, a large papilhc, just iu front of and covering the vulva ; e, anus. 

Fig. 2. Adult male, xG. 

Fig. 3. Head : a, two barb-like papillio ; b, mouth ; c, lesophagus ; d, iutestine. 

Fig. 4. Eggs, highly maguilied: a, eggs before they have left the ovaries; b, egga 
showing nuclei ; v, eggs after they have passed through the oviduct ; d 
egg with one cell; e, with two; /, with four; tj, with eight; h, with 
many; i, egg as it is laid. 

Fig. 5. Skin, showing nine of the eighteen longitudinal lines. 

Fig. (i. Portion of female: a, the intestine; b, h, the ends of the ovaries. 

Fig. 7. Caudal eud of female : a, the anus ; b, the vulva ; c, vagina ; d, d, uteri 
tilled with eggs ; e, oviduct ; /, /, ovary ; (j, iutestine. 

Fig. 8. Spicula, enlarged. 

Fig. y. Bursa, expanded to show costic : a, ventral ;&, veutro-lateral ; t, lateral ; d, 
dorso-lateral ; e, dorsal ; /, sjiicula. 

Fig. lO.G roup of adult males and females, natural size. 

Fig. 11. Caudal end of male : a, bui"sa; i», spicula ; c, seminal reservoir ; d, iutestine. 



PL^iTE XVIII 




c/ -^W C 



Geo. Marx, dd. 



STRONGYLUS CONTORTUS, 
(Tne Twisted Stomach Worm.) 



INTESTINAL ROUND WORMS. 

Sheep in this country harbor at least six species of round worms, 
parasitic in the small and large intestines, which their ancestors brought 
with them from Europe. They are : IStroiigylusJilicolliSjRiul.', Stronfiy- 
lus ve/i^ncosMs, Rud., both found in the duodenum ; Dochmius cernuus, 
Creplin, found in the small intestine; Ascaris liimbricoides, Linn., also 
found in the small intestine; Trichocephalus affinis, End., found in the 
caecum; Sclerostotna hi/postomum, D'wsmg, found in the large intestine. 
A seventh species, (Esophagostoma Columbianum, Curtice, is found in 
the large intestine and is probably indigenous to this country. Of all 
these the last species produces by far the most injury. Dochmius cer- 
nuus is next in im[)ortance. The injury inflicted by the others may, at 
times, and in conjunction with other parasites, be considerable ; but 
disease which may be ascribed to either species alone has not yet been 
rej)orted. From personal observations it is believed that the number 
of individuals in each sheep are usually too few to ever cause extensive 
loss, and that their greatest harm is from the little discomforts which 
they may add to those produced by the more destructive parasites. 

At certain seasons of the year some of the above species are abun- 
dant, while at other times but few individuals may be found. Strongij- 
lus fiUcolUs and S. vcntricosus are usually found associated together, but 
are so small that they can easily be ove-rlooked, or if found may be re- 
garded as the young of other species. Dochmius cernuus is about an 
inch long, and being large is readily detected. Ascaris lumbricoides is 
rare, having been met with only a few times by helminthologistsin any 
country, and in but one lot of sheep by the author. Trichocephalus 
a.ffinis is usually found in young sheep, but is met with in comparatively 
small numbers. Sclerostoma hypostomum seems to be a rare species in 
the East, the single instance in which it was met with in these investi- 
gations being in examining an old sheep in Colorado. (Esophagostoma 
Columbianum seems to take the place of the last-named species in the 
East, and is found most abundantly in spring and summer in its adult 
state, although it is present throughout the year. The most favorable 
time for collecting mostot these species has been in late fall and win- 
ter. The quantities in which the various species may be found vary 
with the season and the flock examined, so much so that no accurate 
statements of percentage of occurrence or of distribution can be made. 

The symptoms which these worms produce are those of general debil- 
23038 A p 10 145 



146 

ity and indigestion. They Are caused by the irritations set up in the 
intestines by the worms. It is found as a rule that a weakly shee[) is 
attacked by more than one species of parasite at a time, and, conse- 
quently, it is difficult to learn the symptoms produced by either of them 
acting alone. Then, too, it should be remembered that symptoms are 
sometimes incorrectly attributed to parasites when they really result 
from diseases due to entirely different causes. Even the fattest sheep 
harbor a few parasites, and some of them many more than one would 
suspect from their apparent good health. 

The treatment should be directed toward keeping animals in good 
health and in preventing them from acquiring parasites by providing 
them with pure water and pastures which are not overstocked. Medic- 
inal treatment will rarely be attempted for any single species of these 
parasites. A remedy which would prove effective for any one of them 
would d o for all. Their treatment will therefore be embraced under 
that for Dochmius cernuus. 

Strongylus filicollis, Eud. 

Plate XIX. 

Description. — Male, 8 to 15'"'" ; female, IG to 24""". Body very small ; cepbalic eud 
thread-like aud tortuous ; caudal end, especially of female, thick and straight. Skin 
marked by loiigitiuliiial lines stauding at about equal distances apart. Head very 
small, subspherical, continuous, with a swollen cylindrical neck;. the length of the 
iudated portion is about one-fourth that of the (esophagus. Four head papilhe visi- 
ble; the lateral papilUe are probably present, but can not easily be made out. Mouth 
terminal ; apparently without chitiuous armature. ffiesoi)hagus linear spatulate ; 
unicellular gland ducts present. • Position of ventral cleft not determined. 

Male: Filiform and uniform in size throughout its length ; bursa strongly bilobed ; 
the membrane being well filled ou the dorsum but absent on the veutrum ; can not 
be spread without tearing; cost;e generally symmetrically arranged, ventral slightly 
separated; ventro-lateral either joined to lateral or ventral ; lateral scarcely sej)a- 
rated; dorso-lateral joined to the dorsal, dorsal notched and with the dorso-lateral 
form a stem, the two pairs uniting to form the dorsal stem ; the lateral costre are the 
longest. Spicula 1..^)""" long, cylindrical, very slender and dark colored ; their 
points are tipped with an oval inflation of the membrane and are more or less firmly 
attached. 

Female: Tail obtuse; vulva situated about one-third of the entire length of the 
worm from the tail; body of the egg-bearing female enlarged in front of the vulva 
by the swollen and crowded uterus. Uteri directed each way from the vagina, and 
filled with comi^aratively few and large eggs in all stages of segmentation. Eggs 
0.i7ium long, 0.08'"'" wide, ovoid ; laid in the morula or gastrula stages. Embryo not 
observed. 

This species occurs with Stromjylus ventricosus in the upper eud of 
the small intestine of sheep and lambs. It is often mistaken for the 
young of other si)ecies, and has been identified as a variety of Strongylus 
conlortus. It is needless to observe that it is specifically different from 
any other nematode found in sheep ; a glance at the plate illustrating 
the species is sufficient proof of this. It is quite abundant during fall 



147 

aud winter. European observers seem to find it rather infrequently. 
The species appears to be a comparatively harmless one. It is probably 
the young of this species which Wedl found associated with Ttvnia 
expansa, and named Tricho so ma papillosum. Wedl characterized it as 
having a double uterus aud the mouth furnished with four papillse. 
Neither of these characters is inconsistent with Strongylus Jilicollis, 
while the fact that Wedl's species, with a double uterus, was classified 
in a genus which has a single" uterus aud spicule indicates an error. 



148 



STRONGYLUS FILICOLLIS, Rud. 

Plate XIX. 

Fig. 1. Adult male, natural length iiulicateil byline: a, head; b. bnrsa and spieiila ; 

c, worm enlarged twice. 

Fig. 2. Adult female, natural length iudieated byline: a, head; b, vulva; c, anus; 

d, worm enlarged twiee. 

Fig. 3. Head: a, mouth surrouuded by four papilhe ; b, tcsophagus ; c, inflated skin 
surrounding head and neck. 

Fig. 4. Skin: shows nine of the eighteen longitudinal lines. 

Fig. 5. Cephalic end : a, the head ; b, the tcsophagus ; c, c, the unicellular gland 
ducts. 

Fig. 6. Bursa: a, the spicula ; b, their knobbed tips. 

Fig. 7. Portion of the spicula enlarged. 

Fig. S. Ovary of female with inclosed eggs showing segmentation. 

Fig. 9. Bursa spread out: «, ventral costai ; b, veutro-lateral ; c, lateral ; d, dorso- 
lateral ; (', dorsal. 



PLSTE XIX 




Haines, del. 



STRONGYLUS FILICOLLIS 
(The Thread-Necked Worm.) 



149 



Strongylus ventricosus, Ru(1. 

Plato XX. 

Deseripiion. — Male, G'"'" ; female, 13'"'". Body very small and comparatively stout. 
Males and young femalt^s usually si)irally coiled; body of old female straight, with 
cephalic end coiled. Slcin transversely striate, marked by fourteen longitudinal 
lines; the five larger standing at equal interspaces on the dorsal and ventral sur- 
faces, the two smaller standing close together on the sides. The crossings of the 
striiB and longitudinal lines make pits which are quite chai'acterislic. Head little 
larger than neck, but hemispherical and coutiimons with the cylindrical inflation of 
the neck. No head or neck papilLe visible. Mouth terminal, very small and round. 
The end of the head is furnished with a hemispherical cap-shaped chitinons piece. 
Other oral armature apparently absent. Inflated portion of head about one-fifth the 
length of oesophagus. Unicellular glands not apparent. Male about one-half the 
length of female ; bursa conical and bilobed, the ventral membrane being narrow, 
the dorsal wide; ventral costaj not separate, smaller than the ventro-lateral, which 
is stout; lateral widely separate and apparently formed of three nearly equal costte; 
dorso-lateral slender; dorsal notched at the end and giving oli' laterally a very short 
side branch. Spicula 0.35'"'" long, short and stout, and margined by a fringe-beari no- 
sinuous membrane. They are tipped by a soft pad-like expansion of the membrane. 
F(;male characterized by a swelling at the vulva, which gives the species its name. 
This character is more pronounced in older specimens. Vulva from two-ninths to 
one-third of the entire length of the female from the tail. Uteri directed anteriorly 
and posteriorly from the vagina. Ova 0.13'"'" long, 0.07'"'" wide, comparatively 
large, and found in all stages of segmentation. Embryo not observed. 

Tliis species is found in association with Strongijlus fiUcolUs iu tlie 
upper part of tlie small intestine of sheep. It can be separated by its 
smaller size, its spiral twist, and the markings of the skin. It is best 
found in fall and winter. The species was originally described from 
specimens taken from cattle, and so far as known has never before 
been noticed as being found in sheep. The female in its adult stage re- 
sembles the small specimens of 8. fiHcnUis. It is apparently the cause 
of little or no disturbance, altliougii from the appearance of its mouth 
parts it might seem to be more injurious than 8. filicolUs. 



150 



SrRONGYLUS VENTRICOSUS, Rud. 

Plate XX. 

Fig. I. Male, uatiiral size indicated by line audsiuill ii>^iiro of worm: a, head; h, 

bursa and spicnla. 
Fig. 2. Female, natural size indicated by line and small figure of worm: a, head; 

b, genital orifice. 
Fig. '^. Head: a, mouth; bb, chitinous cap surrounding it; c, (esophagus. 
Fig. 4. Portion of skin showing eight of tlie fourteen lines: a a, the two lateral 

lines: b b, the dorsal and ventral lines. The dots indicate depressions 

where the longitudinal and the latitudinal lines cross. 
Fig. f). Cephalic end: a, head; b, €eso])hagus. 
Fig. G. Spiculum: a, its chitinous portion; b, the protractor muscle; c, the fringe 

edging the membranous portion ; d, the distal end covered by membrane. 
Fig. 7. Female, natural size indicated by line: This female is more characteristic of 

the species than that of Fig. 2, but is not quite mature. 
Fig. 8. Bursa with spicnla. 
Fig. 9. Bui'sa spread out: a, ventral cost;© ; b, ventro-lateral ; c, lateral, of which 

there seems to be an accessory branch ; d, dorsal-lateral; e, dorsal, which 

also has an accessory branch. 



PLSTE XX 




i IMCL 



•5 liiilf 






« ; = :,' O 





>-:#/ 






':« «.): 



If 



hK 



'I A • 



\ V-e 



Haines, del. 



STRONGYLUS VENTRICOSUS 
(The Ventricose Worm.) 



THE LARGE ROUND WORM. 

ASCAEIS LUMBRICOIDES, Linn. 

Plate XXI. 

Description. — Male and female 150""" each ; in the specimens figured 120 each. Body- 
very large and thick, obtuse at each ead, of a yellowish color, skin marked by rings. 
The site of the vulva is marked by a smooth wide baud about one-third the entire 
length from the head. There are three longitudinal bauds ; the two wider are nearly 
lateral ; the third is ventral. The head end is abruptly terminated in three well- 
formed lips; the dorsal possesses two papilLe near its base and the two ventral one 
each. Each lip consists of a (ihitinous support covered by cuticular membrane. The 
tail of each is obtuse. The description after Schneider {Monographie d. Nematoden, 
p. 36) is as follows : 

" Lips nearly equal, their form changing from semi-circular to quadrangular. Teelh 
very tine. The lobes undivided. The azygoa lobe has a rounded point, and reaches 
with its anterior end to the front of the saddle. Cuticular rings longitudinally ribbed, 
Vulva 40 to 6.V"'" from the cephalic end. Vagina U""'" long. Tail of the male flat on 
the ventral side. Only behind the anus is the skin broadened into a bursa; sixty-nine 
to seventy-five papilhe on pach side ; the first seven pairs of these papill.B stand behind 
the anus ; the second pair stand nearer the ventral line than the first and third ; the 
fourth and fifth pairs and the sixth and seventh pairs are united into double papillic. 
(See Fig. 7.) The succeeding stand first in a single row, then in pairs forming a 
double row; and on the whole they are very irregular. An unpaired papilhe stands 
in front of the anus. Spicula two, each a single tube, with its point terminating 
bluntly and irregularly in front. 

"This parasite occurs in the small intestine in man and swine, and sometimes 
forces its way into the gall ducts, stomach, oesophagus, nose, and lungs." 

In one flock of sheep only has the author found this parasite. In this 
flock it occurred in six animals, a majority of those examined. That it 
is not a common parasite is attested by the writings of various Euro- 
pean helminthologists. A few of the latter have described a special 
species {Ascaris ovis), from the sheep, but as it is infrequently found it 
seems to be an inconstant parasite or an adventitious one, i. e., it is 
probably a constant parasite of some other domesticated animal, and 
occasionally only becomes parasitic on sheep. Besides, the specimens 
figured always seem to have been immature, and do not difier from 
Ascaris lumhricoides of the same size and age. 

In the single flock in which this worm was observed all the specimens 
found were immature. The vegetative organs of these specimens dift'er 
in no essential point from those of Ascaris lumhricoides as figured by 
various authorities. In addition, a close comparison of these specimens 

151 



152 

with equally immature Ascaris taken from pigs gave no determinable 
difiterences. These remarks i)resiii)pose that A. lumbricoides of man 
and A. suilla of swine are identical species. The description seems to 
be incomplete, but as the species is neither peculiar to nor commonly 
found in sheep no attempt is made here to enlarge it. The species can 
easily be determined by a comparison with the figures. 

Sheep probably acquire this parasite while pasturing after swine. 
As few are infected, little harm is accomplished by the Ascaris. It is 
more abundant in summer and fall than at other seasons. 



154 



ASCARIS LUMBRICOIDES, Liuu. 
Plate XXI. 

Fifj. 1. Adult male, natural size. 

Fig. 2. Adult female, natural size. 

Fig. 3. Top view of head enlarged; a, dorsal lip with two papilUe ; h, h, ventral 
lips with one papillte each. 

Fig. 4. Head, ventral view. 

Fig. 5. Head, dorsal view. 

Fig. G. The lips greatly enlarged and flattened: a, a, papillie ; b,b, the serrated 
edge of chitinous support. 

Fig. 7. Tail of male, ventral vi6w : a, anus; 1, 2, 3, 4 and 5, 6 and 7, the post- 
anal papillir"; 8, the unpaired pre-anal ; 9, y, 9, other papilhe. 

Fig. 8. The two spatulate spicula: 8a, one of these enlarged. 

Fig. 9. Portion of female: a, the geuital opening; b, the ventral line; c, one of the 
two lateral lines. 

Fig. 10. Tail of female, lateral view. 

Fig. 11. The same, ventral view. 



PLHTE XXI 




Baines, del. 



ASCABIS LUMBRICOIDES, 
(The Common Round Worm.) 



t. To. l.ilh . R.-aiii 



155 



DocHMius CERNUUS, Creplin. 

Plate XXII. 

Description. — Female, 20 to 26""" ; male, 13 to 17""". Body very dark colored ivhen 
fresli ; whitened when preserved; attenuate towards the ends. Head cnrved, the 
mouth heing directed dorsally. Month round, smaller than the oral surface, and 
opens into an ovoid dark-colored capsule. About the opening stand four teeth, two 
on each side, their base being sunk into the capsule and their free edges projecting 
into the cavity. Tlie ventral are the larger, thiclcer, and more opaque ; their edges 
form an unbroken sinuous line. At the caudal opening of the capsule are one pair of 
ventral and a single dorsal tooth; the latter is conical, very large, and rises to near 
the mouth. In the pharyngeal opening are six very small club-shaped, spinous, 
chitinous appendages of the oesophageal supports or rods; they seem to be jointed. 
TIjere are six papillte — dorsal, lateral, and ventral pairs. The lateral may give off 
a branch on the dorsal side. There are two lateral neckpapilhe, nearly opposite the 
middle of the oesophagus; the ventral cleft is situated a little anterior to a line con- 
necting the latter. Unicellular neck glands quite plain. 

Male: Bursa funnel-shaped ; will not spread without tearing ; costo' unsymmetrical 
as to form; ventral pair not separated ; lateral, widely separated; dorsal notched ; 
dorso-lateral unequal in length and differently attached to the dorsal stem. Spicula 
O.G""" long, aculeate, fenestrated, and provided witli a narrow membranous margin. 

Female: Vulva about three-fifths of the entire length of the body from the end of 
the tail. Vagina opening at right angles to the side of the body. Uteri, lying one 
anterior, the other posterior ; each forms an S'^il^*^ loop; the anterior ovary is di- 
rected towards the tail, and, with the posterior, forms an intricate sinuous net-work 
surrounding the intestine. Eggs elliptical ; laid in the morula stage; length, 0.06™™; 
width, 0.03">">. 

Occurrence. — This species inhabits tlie small intestine of sheep, and 
attaches itself to the intestinal walls by its stout oral armature — the 
so-called teeth. It lives upon the blood of its victims. 

The life history of this S[)ecies of Dochiniiis has not been determined, 
but there is no reason for supposing it different from that of D. trigo- 
nocephalus, the alliecl species found in dogs. Tliis life history has been 
determined by Leuckart {Bic Memchlichcn Parasiten, Baud II, pp. j32- 
134), and is essentially this: The eggs pass from the dog to the gi^onnd, 
where, in wet places, they undergo a development of the vegetative 
organs. If at this stage the young are swallowed by another dog they 
develop into adults. The development outside the dog may consume 
from three to six days. The worm may then continue living without 
further development for an indefinite time, depending on the conditions 
by which it is surrounded and the favorable opportunities for being 
eaten by the dog. Its development in the dog occupies about two 
weeks. The time consumed may be supposed to be that occupied by 
the development of Doehmius cernuns with approximate certainty. 
Leuckart states that though he saw some of the embryos enter snails 
while in their free living state, that this condition was an unnecessary 
one, and that the worms underwent no development while in the snails. 
It may be that if these parasites can enter the snails, their opportuni. 



156 

ties for safely passing the iiulefiuite time prior to finding tlieir way into 
their final host are increased. 

In my own experiments in keeping a nnmber of lambs in a circum- 
scribed space for five or six months after purchase, and in confining two 
others raised there with them, allowing them no water save such as 
was pumped for them, Doclimius ceniuus were found of various sizes in 
the lambs of each set. The two lambs raised on the place must neces- 
sarily have acquired them there. These parasites either developed to 
a certain extent in the iron watering trough or in little pools which 
could have collected and remained in the yard for a day or two after a 
rain, or the lambs were infected from the dry hill-side of the inclosure. 

The disease can only be diagnosed by the flock-master from a post- 
mortem examination. It has been recommended to diagnose these para- 
sitic diseases from the eggs of the worm found in examining the feces 
by the aid of a compound microscope. Such a plan is very tedious in 
its execution, and impractical save to one already skilled in the work. 

Tlie disease caused by Dochmius cernuus receives little attention in 
veterinary works. This is due, in all likelihood, to the fact that not 
more than two or three hundred of the parasites ever seem to be pres- 
ent in one sheep, and generally there are less than one hundred ; then, 
too, if other parasites are found present the illness would probably be 
ascribed to them. If, however, we may be allowed to infer tlie effects 
which would be caused in sheep from the effects which Dochmius 
duodenalls, a related species, produces in man,* in whom it has caused 
epidemics characterized by progressive anaemia, and if we may accu- 
mulate corroborative evidence from the disease which Dochmius trigo- 
nocephalus, a third species, j)roduces in dogs, we may fairly infer that 
the species causes more disease than has been suspected. Nor is its 
comparative paucity in individuals any contraevideuce, for in human 
patients affected with this disease the species is represented by usu- 
ally less than a hundred specimens, although as high as two or three 
hundred have been found in one patient. In dogs the author has 
found about the same number. 

The intestinal lesions are obscure to the unaided eye, except at those 
poiuts where the parasites have been attached. Here, if the worm has 
recently loosened its hold, there is a slight blood extravasation. The 
parasites maintain their hold by the chitinous cup with its projecting 
oral teeth, and in some way cause a hemorrhage, upon which they feed. 
The six pharyngeal spinose appendages may aid in wounding the deli- 
cate epithelial cells. 

It seems impossible that a dozen or twenty, or even fifty, specimens 
of Dochmius could, b^" creating such little injuries in withdrawing blood 



157 

from its host, cause the severe disease aud progressive auaeuiia ascribed 
to it in man, but such has beeu deteruiiued to be the fact from cliuical 
and post-mortem observalious. It may be that there is a reflex, sj'mpa- 
thetic action stimuhited by them of which we can take no account. 
The further changes observed in patients affected with Bochmius are 
much the same as in tliose aft'ccted with other parasites, except that 
anaimia with its attendant eifects seems to be the most prominent. 

The disease is one which begins in early lambhood and i^rogressively 
continues, the severity depending on the number of parasites entering 
the intestinal canal. The adult probably lasts through the winter aiul 
continually lays eggs which pass to the ground. The character of the 
season, of pasturage, and of tlie water, in being either favorable or 
unfavorable to the preservation of the young worms while on the ground, 
will therefore determine the amount of infection and sickness during 
the following season. 

The preventive treatment for the intestinal worms is the same as that 
advised for the lung worms — good care, pure water, i)lenty of grass, 
sufficient grain feeding, salt, anil separation of sick from the well. For 
the reason that the disease has not received the attention its impor- 
tance demands the medicinal treatment has not been worked out with 
the thoroughness that some of the other parasitic diseases have re- 
ceived. 

Medical treatment. — In man the most eflective remedy is extract of 
male fern, combined with powdered male fern, the remedy to be pre- 
ceded five or six hours by a dose of castor oil. This combination is also 
a good one to administer to dogs in the following proportions: Extract 
male fern, 40 grains ; powdered root of male fern, 75 grains. This mass 
must be made into ten pills with yellow wax, and all given at once. 
The dose of powder of male-fern root for sheep is from 1.^ to 3 ounces, 
and of the extract from 2 to 4 drams. As boluses are not only incon- 
venient to give to sheep, aud do uot pass directly into the fourth 
stomach, the administration should be by drenching. I should advise 
that the extract be mixed with from 2 to 4 ounces of castor oil. Other 
remedies advised for the round worms are wormseed, wormwood, and 
santouine. The latter is an alkaloid obtained from a species of Ar- 
temisia. As the lirairie lambs love to eat sage, of which there are a 
number of species belonging to the genus artemisia, it is likely that 
these plants may prove beneficial to theui through medicinal qualities. 
In my examinations of Western prairie sheep I do not now recollect hav- 
ing met with as many round worms as are found in Eastern sheep. The 
dose of santonine for sheep is from 1 to 3 grains, given in from 2 to 4 
ounces castor oil. The preparations of taiusy, Tanacetum vnlgare, have 
long been used as vermicides. The dose of the oil is from 1 to 2 drams, 
given diluted by adding from 4 to 8 ounces of another oil. The receipt 
for Spinola's worm cake sufficient for one hundred sheep is : Take of 



158 

tiHisy root, calamus root, and tar, of each 2A poiiuds, of coiiiinon .salt 
1;^ pounds, make iuto cakes with meal and water, and dry. The (h)se 
ofareca-niit powder, which is an effective reiiiedy for round worms as 
well as tape-worms, is from 1 to 3 drams for lambs. 

The oil of turpentine has proven of itself a valuable anthelmintic;, but 
should be used with care. For intestinal round worms in sheep from 1 
to 4 fluid drams may be given, according to age. The turpentine should 
be mixed with from 2 to 4 ounces of castor oil. Sweet or linseed oil 
may be substituted, but their cathartic effects are untrustworthy. More 
than one dose should not be given until two or three days have elapsed, 
when, if it is deemed advisable to give a second dose, no untoward re- 
sults having been noticed from the first, the dose, slightly increased, may 
be rei)eated. Do not give more than the maximum dose. Tellor (Dis- 
eases of Live Stock) gives the following recipe: Linseed oil 2 ounces, 
oil of turpentine one-half ounce, for a drench. The French veterinari- 
ans advise, among other remedies, the use of emi)yreumatic oil, petro- 
leum, and chimney soot. Empyreumatic oil is animal oil, a by-product 
of distillation of animal matter for ammonia. Dippel's ethereal extract 
is a refined product, and the oil of Chabert consists of animal oil 1 part, 
turpentine 3 parts. The medicine should be administered as a liquid. 
The dose of animal oil, or oil of Chabert, is from 1 to 2 drams, to be 
given in 4 ounces of the chosen vehicle. The oils and alcohol dissolve 
animal oil, but if the vehicle is a watery mixture it must be well 
shaken. Bitter vermifuges made up into tea are excellent, as is also a 
decoction of chimney soot thickened by dextrine or the yellow of eggs. 
From the certain effect that petroleum has on insects externally we may 
infer that it should prove a valuable anthelmintic internally, if it may be 
given in sufficiently large doses. It has been used in man for Uvnia 
and round worms. The dose is 30 minims. The dose for sheep may be 
as large ; how much larger future experiments will determine. Until 
the toxic dose is learned it should be given with caution. It is proba- 
ble that 2 dram doses may be used. Give with from 2 to 4 ounces of 
sweet, linseed, or castor oil. 

Besides these there are many other remetlies proposed, as savin, 
sabadilla, spigelia or i^ink root, aloes, tartar emetic, asafetida, azeda- 
rach, kousso, kamala, and pumpkin seed. The greater part are of 
doubtful etiicacy; others are dear, and can be replaced by remedies 
equally as good and cheaper. Many of the bitter herbs may be pow- 
dered and given with grain, but the sheep will not get enough to have 
the best effects. Often the worst-affected lamb will not eat any, or very 
little, on account of loss of ap[)etite. This method of administration is, 
besides, wasteful. The uncertainty of sheep receiving a full dose is the 
chief argument against such a method. The effect of some of these 
plants on sheep is also modified by the fact that sheep are plant eaters 
and become more or less accustomed to the various medicinal principles 
found in them. 



160 



DOCHMIUS CERNUUS, Crepliu. 
Plato XXII. 

Fig. 1. Adult male, X 1' : 1", natural size. 

Fig. 2. Adult female, X 9 : 2(i, natural size ; b, vulva. 

Fig. 3. Cephalic eud of male, ventral view : a, head ; b, b, resoi^hagus ; c, c, neek 
papillai ; d, opposite ventral cleft out of which the unicellular gland 
ducts e,e, empty hy a common tuhe, /; <j, unicellular glands; h,h, tvro 
ends of the seminal tubes ; i, i, i, seminal tube ; k, k, intestine. 

Fig. 4. Head, dorsal view : a, mouth; i», 6, the chitinous oral teeth on the left side; 
c, c, c, three papillie on right side ; d, dorsal teeth ; e, e, neck glands ; /, 
(esophagus. 

Fig. 5. Head, right side. Letters as in Fig. 4: g, ventral teeth; h, chitinous 
capsule. 

Fig. 6. Pharynx and lower part of capsule of head, ventral view : «, the cut edge 
of capsule; b, the dorsal tooth; c, c, ventral teeth ; rf, pharynx, in which 
are six club-shaped bodies, which seem to- be appendages of the chiti- 
nous rods of the (esophagus; e, oesophagus; /, enlarged club-shaped 
body, which is chitinous and coA^ered with rough points. This apparatus 
seems to be for mastication. 

Fig. 7. Middle portion of female, X30: a, vulva; b, vagina; c,c, portions of cephalic 
uterus ; d, d, caudal uterus with eggs; c, oviduct ; /,/, cephalic ovary ; </, </, 
caudal ovary ; /(, h, intestine. 

Fig. 8. Eggs: a, o, from ovary; b, in oviduct; the rest from the uterus in various 
stages of cell division ; c, as they are expelled. 

Fig. 9. Bursa: a, ventral costte ; b, ventro-lateral ; c, lateral; d, latero-dorsal ; e, 
dorsal. The two sides are uusymmetrical. 

Fig. 10. Spicula. 

Fig. 11. Portion of spiculum showing fenestrations and openings into the tube : a, 
tube ; b, wing. 




PLSTE XXII 



2 t 



2 all 



Baines, del 



D0CHMIU8 CERNUUS, 
(The Bent-head Round Worm.) 



161 



SCLEROSTOMA HYPOSTOMUM, Dlljaidiu. 
Plate XXIII. 

Description. — Male, IG^""^ ; female, 24""". Bod^' white, cyliudrical, and stonfc. Head, 
globular, a little veiitrally curved and truncate at the mouth; head papilhe six; 
neck jiapilhe not observed; ventral cleft about opposite the end of the second fifth 
of the oesophagus, counting from the head. Uuicellulai glands and lateral lines very 
conspicuous. Month-oi)ening round, obliquely inclined; surrounded by a single 
circle of very minute saw-like teeth. The globular chitinous capsule is marked by 
numerous longitudinal elevations, which are stronger at its bottom. The posterior 
opening is circular, unarmed, but roughened. Around the mouth is a circular canal 
which empties into a dorsal canal. There is apparently no pharyngeal apparatus as 
in Dochmiiis. ffisophagus slightly swollen caudally. Two lateral dnctaopening near 
the mouth and situated on either side* of the head are apparent; they seem to end 
caudally in the lateral canals. Male about two-thirds the length of the female. 
Bursa shallow, set on obliquely, campauulate. Ventral costte either separate or 
slightly so ; lateral slightly separate if at all ; dorsal pair irregular and widely sep- 
arate; the dorso-lateral and dorsal forms a single stem with three lateral branches. 
Spicula l.r>""" long, linear aculeate, cioss-striated, and bordered by narrow margins 
which roll in towards each other. Two anal papilhe. Female stout and thick, and 
usually with a brown crust near the vulva. "Vulva very near the tail. Tail full to 
near the end, but ending in an acute mucronate point. Uteri directed toward the 
head; one, the caudal, makes a loop at the tail. The ovaries show loops near the 
tail. Eggs elliptical, O.!'""" long, 0.0(5'"™ broad, laid m the gastrula stage. Embryo 
not observed. 

Occurrence. — Sclerostoma hypostonmm is found iu the large intestine 
of raminaiits. It is present associated with (Esopliayostoma Colum- 
bianum in sheep iu this country, but not abundantly. It is closely re- 
lated to Sclcrostoma equimim of horses, a species said to make tumors 
iu the intestines. As S. hypostomum is rare, it has not yet been deter- 
mined whether it causes intestinal tumors in sheep. Since 8. tetracan- 
thum, whose embryos make tumors in the ctx^cnm of the horse, is more 
nearly related generically to Q<]sopha(jostoma than to Sclerostovia, I am 
inclined to believe, as I have proveu in regard to GiJsophaf/ostoma Colum- 
bianum iu sheep, that the species belonging to the genus (Esophayostoma 
are intestinal — tumor-making j)arasites rather than those of Scleros- 
toma. 

Life history. — M. Baillet {Nomean Diet, de Med. T. VIII, art. Hel- 
minthes., 188G) is aulliority for the following: 

The sclerostome of ruiuinauts is reproduced in the same way as that of solipeds. 
Its eggs, of which the vitcllus is segmented in t'.io uterus of the female, are laid in 
the large intestine and carried without by the fecal material. Tliey are hatched after 

23038 A P 11 



1G2 

a few (lay.s, and l.lio eiiihryos iiro very similar in tlicir geucial form to tlmseof iSc/eros- 
toiiKi tclracitntham. Tlicy ar(} cyliiKlroid, ^slll)ul)^lI.sc at llic anterior ixtriMuily, and 
jiruvitk'd with a narrow tail much nIiorttM- tlian (hose of the yoiiiiii.sc/f /•«;»/omts of the 
liorM«\ Tliey move, be.sid<;.s, iu the ^sam(! manner a.s the latter. Tliey can live a lonj^ 
time, in the fecal material of ruminantn when they are not drieil, and in (Iiis condition 
they j;row. Some young Schrostotiux which, after hatching, were O.I{r)""" h>ng to 
0.50""" have been found in the drop|iitig,s of .sheep. After having been kept damp two 
and a half mouths these were from O.CHJ to 0.78"'"' long. Their skin, which is folded 
on the surface of tho bod}', appears to indicate that, like the SvAerotftomcs of the horse, 
tht'v are jireparod to undergo a molt. The young Sclerostoma hy2)ostomHm can live a 
long time iu water after having reached a definite size iu the fecal material of rumi- 
nants. 

Wo have not yet observed cysts within tho mucous membrane of the large intes- 
tine of sheep.* But as the Sclerostoma hypostomum are in far less niirubers of 
ruminants than S. eqniniim or S. tetracauthitm in the horse, wo can not yet draw 
any conclusion from the negative result of our researches. Wo will not say then at 
present whether the Sclerostomcs of ruminants pass the second pllas(^ of their exist- 
ence in cysts, or whether they are developed in tho intestinal canal itself in tho 
midst of alimentary material which is found contained there. The eggs of the Svle- 
70>ito)ncs of ruminants taken directly from the nterus of females and preserved in 
water at a temi)eraturo of from 12 to 20" C. (about 55 to 70^' Fah.) hatch at the end 
of four or live days after having undergone all the series of successive modifications 
which are alike observed in the eggs of Sclcrosfomes of 8olii»eds. 

The only possibility of error in Baillet's experiments is tlie intleiitifi- 
ciitiou of the species with which he was dealing', for he writes: 

It (5«e^')v<,s7o«(rt /(^/jw^/o/HHWi MS above all very frequent in sheep. There are often 
found individuals, probably younger, whoso month, entirely terminal, is less widely 
open, and provided with a single rank of teeth still loss numerous. These worms 
also lack a pharyngeal capsule, and often carry a membranous swelling on the sides 
of the head. 

The above describes (Esopha/jofitoma vemdosum quite well, and when 
the learned helminthologist did not experiment with eggs taken directlj' 
from the adult worm he may have had to do with the eggs of either. 
This would account for the similarities found between some of the 
young embryos experimented with and those of Sclerostoma tetracan- 
ill urn. (The author is of the opinion that the last named species should 
be classed with the CEaophagostoma instead of the Sclerostoma.) 

The life history of this species is, that the eggs are scattered by the 
sheej), that they then dexelop somewhat, and without the need of any^ 
secondary host are capable of further development in sheep when taken 
by them along with tlie food or drink, and that in the large intestine of 
the latter they may or they may not make tumors during their embry- 
onic stages. 

The prevention and treatment is the same as for other intestinal 
worms. 



* This indicates that (Enophatjoxtoma ('olumhianum has not been observed in France. — 
C. C. 



164 



SCLEROSTOMA HYPOSTOMUM. 

Plate XXIII. 

Fig. 1. Male, XH. Fig. la, uatural size. 

Fig. 2. Female, x8. Fig. 2a, uatural size. 

Fig. 3. Head, ventral view : a, the capsule ; ?>, the dorsal canal ; c, lateral ducts ; d, 

fBSopliagns. 
Fig. 4. Head, lateral view : a, c, d, as in Fig. 3; p, the three head-napilhe ;/, the coni- 
nion duct of the joined unicellular gland ducts is placed near the veutral 
cleft; g, the end of the wsophagus, showing three dependent lips; h, the 
cut-end of the skin. The drawing shows the longitudinal muscular band, 
separated into two groups l)y the lateral canals, i, i, and the three separa- 
tions of the muscular bundles between these canals which ai)pear on the 
surface as lines : k, k, k, cut end of the intestine. 
Fig. 5. Head, dorsal view: a, h, c, and d as in Fig. 3. 

Fig. G. Mouth end of lateral half of chitinous capsule: a, a, a, the ventral, lateral, 
and dorsal head papilhe; b, the dorsal canal which continues around the 
head in c, c; d, the mouth, arouud which is a circle of suuiU thorn-like 
teeth, about forty in all. 
Fig. (5a. Teeth enlarged. 

Fig. 7. Caudal end of capsule : o, the cut wall ; b, the dorsal canal ; c, the triangu- 
lar opening of cesophagus. 
Fig. 8. Section of esophagus: a, a, a, tlio chitinous sui)iiort; b, b, b, the walls, c, 
the orifice. 
Male bursa with spicula. 

Portion of epiculai : a, the chitinous cylinders; /), the membranous margins. 
1)6. Diagram of anal jjapilhe. 

Bursa spread out: a, veutral costa^ ; /;, lateral ; c, d(U'sal ; d, the torn edge. 
Caud<al end of female: a, anus; b, vulva; c, c, uteri; d, d, loops of the 
ovaries; e, e, the iutestiue ; /, a dark brown pat(;h usually found on the 
vulva; g, an egg. 
Fig. 12, Cross-section of female: a, intestine; b, ovaries; c, lateral ducts; d, muscu- 
lar bundles (Leuckart). 
Figs. 3, 4, 5, and 6 are somewhat distorted by llatteuing. 



Fig. 


9. 


Fig. 


9a. 


Fig. 


96. 


Fig. 


10. 


Fig. 


11. 



PLATE XXIII 



1« 



4.4 



4 



2a 



d. . 



■'-^ 



■Vv\^^^ 



Ijj 



w 





h 


k 




\^oi 




J2 , - - 


11 


^ ^ .''' 







Haines, del. 



7 -- 
SCLER08T0MA HYPOSTOMUM 



THE NODULAR DISEASE OF THE INTESTINES. 

CEsoPHAGOSTOMA CoLUMCiANUM, Curtice. 

Plates XXIV, XXV, XXV[, XXVII. 

In the Eastern States there exists a hitherto undescribed disease, 
which is characterized by tumors present iu the upper part of the large 
intestine. The disease causes heavy losses, for it seriously affects the 
health of the sheep, and renders the intestine valueless for making- 
sausage casings. Though the latter result would seem trivial at first 
sight, it is by no means unimportant, for sausage-makers are compelled 
to import the greater part of covering material used in their business. 
The disturbancesof health produced are very serious, for there are places 
in the South where sheep can not be kept with i)rofit, api)arently on ac- 
count of this parasite alone. Dr. D. E. Salmon, Chief of the Bureau of 
Animal Indnstrj^, who atone time lived in the South, performed many 
post-mortem examinations on diseased sheep, and found nothing but these 
intestinal tumors to account for the severe symptoms of disease which 
they exhibited, and has verbally stated tiiat he believes this malady is 
the chief obstacle to successful sheep husbandry in some portions of the 
Southern States. 

Investir/ntion. — The cause of the disease remained until the winter of 
1888-'80 in obscurity, but owing to a favorable combination of material 
and methods of investigation it was then ascertained. Some of the 
larger soft tumors, which are characteristic of this disease, were dis- 
sected from the intestine, and after being slit open their greenish, 
cheesy contents escaped in a watch-glass of water. By carefully teas- 
ing the apparently newer portion of these masses a little worm, the 
cause of the trouble, was found. Previous to that time Dr. Theobald 
Smith, of this Bureau, had in the winter of 188G-'87 made and examined 
microscopic sections of these tumors. One of a series of sections (see 
Plate XXV, Fig. 8) showed what was apparently the fragment of a 
worm. Numerous other sections made at the same time showed noi 
signs of this parasite, and the investigations were temporarily aban- 
doned. 

Although tuberculosis is an uncommon disease in sheep, and although 
the tumors found in this disease differ in many essential points in botli 
their history of formation and in their histological <letail from those 
caused by tubercle bacilli, there was a superficial resemblafice, oui 

165 



16G 

account of which Dr. Smith made many tests of the caseous matter for 
the bacilli both by the microscopical methods and by the inoculation of 
small animals. In the light of subsequent investigations it is needless 
to say that these tests had only negative results. In justice to Dr. 
Smith it should be stated that ho undertook the experiments more for 
negative evidence than from any expectation of finding bacilli. 

The came of the disease is a nematode or round worm, which, though 
remarkably similar to some other worms of its groui), is nevertheless a 
distinct species from any hitherto descrilxMl. The failure to find this 
worm in our earliest investigations may be ascribed to two important 
factors. The first is that of the season of obseiv^ation. We had i)roba- 
bly ovciHooki'd those tumors which were best adapted to show the worms, 
but iiKiiidy on account of the season in which the examination was mad;'. 
The method of examination was probably the greatest factor in the in- 
vestigation, for as soon as what may he termed niacrosco[>ic superseded 
microscopic methods the discovery was easy. The method was not en- 
tirely macroscopic, for simple lenses of low power were used. 

The worms found in the largest tumors were never over 3 or 4""" 
in length, and presented only an embryonic development, the vegetative 
organs alone being present. Figs. 1, 2, and 4, in Plate XXV, were 
made from the largest specimens. As the adult worms of this class 
may difler materially from the embryos in the character of the mouth 
l)arts and in their appearance after the reproductive organs have de- 
veloi)ed, the difficulty was encouutercd of connecting the embryonic 
cystic form with an adult form existing in sheep or elsewhere. 

Determination of adult. — The most conclusive method of determining 
the adult would be to directly develop an embryo into an adult, but 
this proceeding was not attempted on account of its difficulties. A less 
satisfactory method remained of finding some adult worm whose em- 
bryo was unknown, and which not only corresponded in structure with 
the embryo, but whose life history was such that it was possible for it 
to be the parent of the embryo. It will not be profitable to detail 
theories advanced to aid in this investigation ; suffice it to say that 
while studying one day a group of wornis which came from the large 
intestines of sheep, I found among them an undescribed species. 

This species was immediately referred to the Sclera stomituv (Itaillet, 
Elements of Zoologie, p. 330), and later to Molin's genus (Esophafjos- 
toma. There may be an impropriety in accepting this name over others 
proposed at the same time for species of this genus, but as the same 
author proposed them, and as the genus is in general use, it is accepted 
in this classification. For reasons assigned hereafter in a description 
of the species I have called it a new one — (Ksopha(jostoma Golumhianum. 
The specific name is from the fact that the worm was first found in the 
District of Columbia. 

The adult worm is fouml in the large intestitie of sheep in considera- 
ble numbers, and iii the same animal may also be foun<l the tumors. 



1G7 

The parasite is usually found below the narrowing of tlie large intestine, 
where the latter changes from a sack-like receptacle to a large tube, 
and below the mass of the tumors. The tumors may, however, extend 
the entire length of the intestine. It is evideut that the distribution of 
the eggs of this adult would be favorable for sheep becoming agaiu in- 
fected by them. 

The oral armature of the embryo from the tumors and the adult (Eso- 
2)hafjostoma Columhianum differ, that of the embryo appearing to l)c like a 
chitinous cup comparable to that found in the youug of the Sclerosfoma 
of sheep and the Dockmlus of dogs. The young of these species, however, 
differ as much from their adult form as the embryo in question does 
from its supposed adult form. 

The anatomical point that the writer considers of the most moment is 
that the embryos of the tumors possess a lapel-like fold on the ventral side 
of the worm just anterior to the ventral cleft, the opening of the unicellu- 
lar gland duct, an«l that the adult O. Golumhianum possesses a similar 
fold identically situated. (See Plate XIV, Figs. 1, 2, and 3, and Plate 
XXV, Figs. 2 and 3.) The absence of this feature in the embryos of 
Hchrostoma and Dochmms that infest sheep at once precludes the possi- 
bility that we have to deal with these species. That embryos of this 
character and corresponding adults are found in the same sheep makes 
the diagnosis more assured. Should we look for a host in some other 
animal we should expect to find one that had all the opprtunities of 
spreading the eggs that infect the sheep, but amongst our farm animals 
we find no corresponding i>arasite, and other wild animals which might 
be suspected as hosts are at the present time very rare. 

CESOPHAGOSTOMA COLUMBIANUM, n. sp. 

Description. — Mule, 12 to 15""" ; female, 14 to 18"'"'. Worm siinilar in ai)pearaiico 
to Docltmius cerniius, but liavinj; its head bout into tho form of a book. Head ter- 
minal, very short, somewhat thicker than tho neck, and separated from it by a con- 
striction. Papilhe six, of whicli two are dorsal, two ventral, and two lateral. The 
latter are more obtuse and are the openin<>s of the lateral canals of the body. Mouth 
terminal, supplied with a chitinous armature, consistin<i; of an annular ring, which 
supports two systems of twenty-four teeth each; the outer circles are very long and 
curved, so that near their base they form a truncated cone and at their free extremi- 
ties an inverted truncated cone. Within the outer is situated the inner and shorter 
row of bidentate teeth, so arranged that each tooth is opposite one in the outer row. 
Benealh the armature is the tri-radiato opening of the o\sophagU8. Neck not inflated, 
but provided with a lapel or fold of skin on the ventral side Just in front of the 
ventral cleft; the fold continues slightly on to the dorsal side. Two latera.l, narrow, 
membranous wiugs begin at this neck fold and continue for one-fourth the length of 
the worm. The two lateral opposite papilhe are in these wings, at the level of the 
first third of the a-sophagus. The pair of unicellnlar neck glands unite into a com- 
moTi duct and empty at the ventral cleft, situated beneath the nuchal fold. Male 
about three-fourths the length of the female. Bursa saucer-shaped ; can be spread 
symmetrically without tearing. CostiB or ribs symmetrical; the ventral slightly 
separated; the ventro-lateral forms with the lat<>ral a group; the lateral also 
slightly separated ; the dorso-latcral forms willi its frllow and the dorsal pair a 



168 

jri'oup; the dorsal rib is composed of two, which are widely separated only towards 
their free euds. Spiciihi two; awl-shaped, bordered by a very narrow meiubrane; 
the chitiuous cylinder is apparently fenestrated. At either side of ihi' ^iiiital orifice 
are two knobbed papilhe. Female relatively stouter; vulva just in front of anus, 
wliich is midway between it and the acutely pointed tail, usually covered by a hard 
brown patch ; reproductive organs in two sj'uunetrical sets anteriorly directed, ex- 
cept a small portion of one, which is at first posteriorly directed to form a loop in 
front of the anus. Uteri two, in the caudal end of the body. These may be traced 
up to the oviduct and ovaries, which coutiuue to the cephalic end of abdomen, where 
they are reflected to form a loop and thence coutinue to the caudal end to form still 
another loop. The ovary of the caudal uterus forms still another loop nearly oppo- 
site the uteri. 

Eggs laid with gastrula inclosed; length, 0.09'"""; width, O.Oo""". Embryos from 
0.23""" upwards. The largest found in tumors were 4""" long; the smallest male 
found in intestiue was 7™"' long. The smallest embryos were without digestive ap- 
paratus. Thelargest possessed an intestine, unicellular glands, and a well-formed 
chitinous spherical cup in the head; also six cephalic papilhe, and at the neck two 
papil!;e and a well-defined fold. 

Occurrence. — The adults live iu the large intestine of sheep below the 
c.neciim; the embryos live in the intestinal walls in tumors, which, 
though more abundant iu the ciiecum, may be scattered from the duode- 
num to the anus. The species is distributed in the United States east 
of the Mississippi River as far north as Maryland, perhaps farther north. 
On comparing the species with others of the genus it was found that it 
corresponded more nearly with CEsophagDStomavenidosum^ a parasite of 
goats, than any other described in modern works, and that it cone 
sponded still more closely with 0. acutum, Molin. {LI sottordlne <Je(jli 
acrofalli. Memorie dell * * * Istituto Vencto, 18G0, I o/. 7A', p. 
449.) The latter is apparently a distinct species, although in quoting 
other authorities he has given an incorrect synonymy. 0. Columhia- 
num diti'ers markedly from 0. vemilosum in not having an inllated uecl;, 
and from the latter and 0. acutum by the possession of a lapel of skin 
upon the ventral side of the neck, just in front of the opening of the uni- 
cellular neck glands. Molin examined two males and three feniales of 
O. acutum from Antilope Rupicapra; one male from Gapra Hircun, var. 
Mambricus, in association with forty-five Sclerostoma hypostomum ; and 
two males and one female from Gapra Amman. The finding of Scleros- 
toma hi/postomum in association with the Q^sophagostoma acutum is the 
fact which leads me to infer that the latter occurred in the large intes- 
tine of the above mammals and not iu the stomach, as he cites in hijs 
synonymy of the species. 

Life history. — (Esophagostoma Golumbianum seems to have become a 
l)arasite of sheep since their introduction into this country. If present 
in the Old World at all it is sparingly so, and seems to have escaped 
detection. So little is known about its distribution, that it is impos- 
sible at present to accurately define its limits. From its great abun- 
dan(;e in the Southeastern States one might infer that it had originated 
as a. slieep parasite in that region, and i)robably from some animal of 
allied organization and hal)its. Tln^ writer is at present inclined to 



169 

believe tliiit the deer may have beeu its host at the time European 
sheep were first iutiodnced. There are few facts to sustain this hypoth- 
esis. Though it may yet be too early to form a positive CDUclusion, 
further investigation may determine the section of the world to which 
this parasite originally belonged and then the former host may be in- 
dicated with tolerable accuracy. 

The life history of this parasite seems to be completely known to us 
during its development from the immature form found in the intestinal 
tumors to the adult stage; but there is a period from the moment 
when the eggs escape from the intestine with the excrement to the 
time when it is found again in the intestinal tumors that must remain 
in obscurity. After the embryo has returned into the alimentary canal 
it makes its way through the mucous coat of the intestine and becomes 
encysted there. The writer has been nnable to learn how it passes 
through the mucous coat, as even on the youngest specimens no sign 
of armature is found. The very young forms found in the cysts show 
little differentiation beyond what they could have attained in the egg- 
shell. They are sooi. surrounded by a cyst which seems to belong to 
them and to have been created by. them ; bnt whether this cyst is the 
remains of a molt or not can not be assorted. Later in their history 
they become surrounded by the products of the inflammation they ex- 
(jitein the surroundiug tissues, and eventually break from the cyst and 
live in the cheesy mass of the tumor. In this stage of their growth the 
worms exhibit the intestine and oral cup and indistinct unicellular 
glands. They then molt, and show all these features in more distinct 
outline. Having attained a length of from 3 to 4'"'", or less than one- 
sixth of an inch, they break from the tumors to begin their life in the 
intestine. In the latter they continue their growth and beconjing sex- 
ually perfect and produce eggs which eventually go through the same 
cycle. 

In developing, this worm molts at least three times — once in passing 
out of the stage in which it has no mouth or intestines, once during 
the development of these parts as we find them in the embryo, and 
once while the worm changes from the embryonic form to the adult form. 

Disease. — The harm that these parasites do the sheep is directly 
dependent on their numbers and life history. Yearlings may show 
considerable infection, but it is usually in older sheep that the most 
abundant infection occurs. The disease is a seasonal one, in that it can 
be found in best development in the winter. The lambs begin to be in- 
fected in the summer and fall, and from that time the tumors formed 
increase in size until early in the spring of the next year, when they 
gradually grow smaller but probably do not entirely disappear. 

Pathology. — A study of the fresh tumors by compressing the smaller 
ones between two glasses and by dissecting larger specimens gives the 
following results: The small tumors, which are scarcely the size of a 
pinhead, are found in the snlMniicous tissue. They appear like a sac filled 



170 

with tliiid and having a little globe fioatiiig witliin. By using a higher 
magnifying pov/er the little globe is seen to be a cyst with a worm 
inclosed (see Plate XXV, Fig. G). By careful dissection the cyst may be 
separated (Fig. 5), and finally the worm itself may be separated (Fig. 3). 
At this stage the worm shows little differentiation of jiarts. In exam- 
ining another and older cyst (Plate XXV, Fig. 7) the same appearance 
may be observed. There is also a little greenish cheesy substance 
present. A third stage (Plate XXVI, Fig 3) shows the latter still fur- 
ther increased, and in the figure referred to the arrow shows that the 
encysted worm has been pressed out of this mass, leaving a cavity be- 
hind. 

When the little tumors become larger than a pinhead and entirely 
filled with the cheesy matter their structure does not materially change, 
but is more dilficult to make out. It is at this stage that the worm 
escapes from the cyst and begins to wander within the capsule which 
its presence in the tissue has caused. On dissecting the large Iresh 
tumors the worm is found in the mass of cheesy material, which is now 
quite abundant, filling the cavity and producing tumors as large as 
the end of one's finger. This cheesy material is usually hard, dry, and 
brown at one end, and soft, yellowish-green at the other. It is in this 
end that the worm is to be found. If some of the harder tumors are 
examined, it may be found that there is no greenish material in them and 
no w^orms. These hard tumors may be of all sizes and are found at all 
times. From these the worm has either escaped or in the case of the 
smaller tumors the worms have died. The form of these tumors is 
usually spherical, but the cheesy material may appear as a long mass, 
or it may apparently fill what seems to have been a worm track. The 
last appearance occurs most often in the small intestines. From the 
mucous side these tumors present little if any color. The older ones 
may present a greenish-yellow appearance, especially if the mucous 
membrane over them be thin. In well-advanced cases, when the tumors 
are numerous and large, many are found in which the mucous membrane 
over them is ruptured and the cheesy mass protrudes into the intestinal 
cavity. In these no worms have been found, and hence the conclusion 
has been reached that the worms have escaped. 

In lambs the little dots indicating the presence of the young tumors 
are very scattering (see Plate XXVI, Fig. 1), but in older shee[> tliey 
may be very numerous (see Plate XXVI I, Fig. 1). Between the stage 
in which a few are scattered here and there over the cjecum ami lh:it 
in which the c:ecum has become a sf ifl" tube with walls from one fourth 
to one half inch in thickness (so thick and close have the tumors be- 
come) there are all varieties. The tumors may extend from the c;ecum 
to the anus. They may also be abundant along the small intestine. 
The cheesy material which the worms produce has been found in the 
lymphatics, on the omentum, and in the liver, but in these places it 
never seems to be sufiiciently abundant to show that the parasite lived 
long. 



171 

Microscopic serial sections made from aicobolic specimens show best 
the changes wliicli have taken phace in the surronuding tissue. On 
Plate XXVI, Fig. 2, there is figured an enhirged view of one of the 
worms still encysted and surrounded by the tumor of inflammation. 
From this section it is seen tliat the irritation setup in the adjoining con- 
nective tissue causes the cells to proliferate and crowd closer and closer 
together. It is also seen that there is a special cyst for the worm and 
a thickened adjoining jiortion of the tumor which is like a surround- 
ing membrane. As these two menibranes, the so-called cyst and the 
outer one, stain so nearly alike, it has occurred to me that they represent 
successive efforts of the adjoining tissue to protect itself against the 
parasite; but in view of the fact that the inner one is so easily enucle- 
ated, it is for the present considered asbelonging to the worm. At the 
foot of Plate XXV, Fig. 8, there is given an illustration of a small 
tumor in which the worm has es(;aped from the cyst and in which the 
surrounding matter has become cheesy, some of it even hard. Around 
the entire mass the tissue is slightly thickened and forms a capsule. 

From these two microscopic sections we can learn how these tumors 
grow. The worm penetrates to the submucous tissue and irritates it. 
The adjoining cells rapidly increase in number and crowd upon each 
other. So closely do they crowd and so numerous do they become, that 
the outer layers cut off the circulation from the inner cells and they 
die. Their degeneration gives rise to the cheesy mass. Now, if the 
worm remained in the center of the mass the new growth would event 
ually cease, but the worm makes its way to the outside and at that 
point keeps up this irritation and new growth. This is shown by and 
accounts for the dried older parts of the larger tumors and the fresh 
yellowish-green adjoining i)arts. As soon as the worm escapes the irri- 
tation ceases, the tumor shrinks, and absorption of the mass begins. The 
irritation produced by the worm provides it with food and favorable 
surroundings for development. Often the worm dies from weakness or 
other cause, and leaves behind those little hard incompletely-grown 
tumors which have been mentioned. 

Since writing the above life history two post-mortem examinations 
have been performed, which lead me to modify my views regarding the 
life history of certain other tumor-making parasites. On August 10, 
1880, two lambs, one five months old, the other eleven weeks old, die<l. 
The older lamb was bred at the experimental farm; the younger was 
bought with its dam when but a day or two old. These lambs had no 
water save what was pumped from a well. Among other parasites, 
each species being found in its proper portion of the intestine, there 
were numbers of individuals of (Esophagostoma scattered through the 
length of the large intestine. These individuals were of all sizes, from 
the smallest stage (7'"'" long) to those nearly adult. In thie younger 
lamb there were but few very minute tumors in the coals of the large 
intestine. In the older the tumors were somewhat larger, but none were 



172 

much larger than a millet seed. Tbe abundance and size of the free 
parasites indicated that most if not all of theiu had developed in the 
interior of the tube. The intestinal tumors indicated that there were 
others developing in them. 

From the above it seems probable that this species develops nor- 
mally in the intestine, that some of the young embryos penetrate into 
the walls of the intestines, and at times even to the mesenteric lym- 
phatic glands and elsewhere ; that those which penetrate into the intes- 
tinal wall either develop very slowly or eventually die, depending on 
the tissue penetrated and the favorable conditions the latter offer for 
the nourishment of the parasite ; that those which develop slowh' may 
in time escape from the tumors and complete their development in the 
intestinal canal ; that this phase of its life history may be one that is 
favorable for the preservation of the species by preserving a few indi- 
viduals in tumors throughout the winter which escai)e in early spring, 
become adult, and lay their eggs, which are scattered on pastures favor- 
able to the preservation of the embryos; that the majority of these 
embryos, penetrating the intestinal walls, wander into such environ- 
ments that they are eventually destroyed ; that this act of migration is 
voluntary and only of benefit to the parasite when the latter becomes 
lodged in the proper place, and that the same power which onabh\s it 
to arrive at these places also enables it to penetrate farther than is of 
use to it; that the slow development of the worm in the tnmors as 
compared with the development in the intestine shows it to be a re- 
tarded development, which may be hastened as soon as the parasite 
again reaches the i)roper surroundings. 

In short, the fact of the intestinal life of these parasites is demon- 
strated, as well as the fact that some may wander into tlie intestimil 
walls and undergo a retarded development before re entering the in- 
testine. 

The diagnosis of this iiarasitic disease can only be made from aposU 
vwrtem examination. In the living sheep there may be signs of general 
debility' — bloodless lips and eyes, thin sides and flanks, dry wool, etc. 
It may be that nothing else will be noticed, but that the flock is not in 
quite good condition ; or in severe cases the diarrhea and emaciation 
may be excessive. Dr. Salmon believes the disease may bringdeath to 
its victims in the severest cases. My own observations have been con- 
fined to the abattoirs, where salable animals only are brought. As tlie 
adult worms are comparatively few as compared with the tumors, it is 
l>r()bable that the adults of this species cause but little trouble; but the 
embryos, on the contrary, cause a groat deal. The disease is an insidi- 
ous one, for not only is the rate of infection gradual, increasing slowly 
in amount from week to week, but the rate of development of the 
tumors is very slow, npparentlj* requiring mouths. It is only when the 
disease is well advanced tliat its cumulative effects can be noticed. 

The disturbance of digestion caused by this parasite is mainly due to 



the derangements of the functionvS of the ccvcum. This derail ;4(Mnent is 
not seiions until the resulting tumors become exceedingly nuiiiiuons, 
well advanced in growth, and press upon the more essential mucous 
membrane, disturbing its functions. 

The most seriously affected sheep found in the abattoirs are notice- 
ably poorer, and one would be tempted to believe, were he to judge from 
the "knotty" viscera, as the butchers call them, that such animals 
shonld have died from the disease long before. These sheep usually 
have diarrhea, a disease which weakens the affected animals. Flock- 
masters who mistrust that their sheep are not doing well, and who 
know of no cause for it, should sacrifice one or two of the poorest to 
make a diagnosis. The meat of such sheep, though not quite as fat as 
other mutton, is suitable for food, and could not be distinguished in the 
market from other mutton. 

Prevention. — For the tumors caused by (Esophagostoina Columbianum 
there is no remedy except the removal and extermination of the adult 
worms. These adults are usually buried deeply in the mucous secre- 
tions and attached to the nie?nbraue of the large intestine. Tliey may 
be found in considerable numbers in older sheep. The medicinal rem- 
edy must therefore be one which will remove them from these i)laces. 
It is probable that such a one can eventually be found, but at present 
none can be recommended. It is probable that some one of the surer 
remedies advised for other intestinal parasites will do for these. In 
case medicinal remedies are tried each animal must be dosed. The 
killing of the adults will of course lessen the number of eggs with which 
the sheep become infested. As the eggs of this parasite pass to the 
ground the sheep may get them either while pasturing or drinking. 
The same care in changing pastures, in providing good drinking water 
and a plentiful supply of salt, should be observed as for other parasites. 
Judicious fall and winter marketing of infected sheep will also tend to 
lessen the chances of infection. If pastures are known to be perma- 
nently infected, theu they should be turned over to other stock for a 
year or two before being again grazed on by sheep. When it is prac- 
tical on the smaller farms the sheep lots should be plowed and either 
planted or left fallow. The object of change of pasture and of plowing 
is nearly the same ; in the one case, to wait until the parasites have 
died out; in the other, to bury them beneath several inches of soil, from 
which the sheep-owner may rest assured they will not emerge. 



174 



CESOPHA.GOSTOMA COLUMBIANUM, Curtice. 
Platk XXIV. 

Fig. 1. Adnlt male, x9, Fig. 1«, uatunil size. 

Fig. 2. Ailiilt female, x9, Fig. 2a, uatural size. 

Fig. 3. Cephalic eml of adult, ventral view: a, head; b, oesophagus; c, lateral 
canals opening ou head; d, unicellular glaii<lH and ducts uniting and 
emptying at e, the ventral oriKce; /, a fold of the skin which forms a half 
ring on the ventral side of the neck ; the orifice e opens nnter it ; t/, y, two 
pointed nock papilhe ; li, h, narrow memhrunous wings; i, intestine. 

Fig. 4. Caudal end of adult female lateral view, x45 (about) : a, anus; b, vulva; c, 
vagina; d, d, uteri ; e, e, oviducts; f,f,f, loops of the ovaries ; i, intestine. 

Fig. 5. Head : a, mouth; b, b, papilke of the two lateral ducts; c, c, two of the four 
acute, pointed papilUe opening on the head ; d, d, cross-section of cavity ot 
tlie head ; e, e, cross-section of a circular canal, which runs around the base 
of the head ; /, chitinous .irmature of the head ; (j, tesophagus ; h, its three 
chitinous supports. 

Fig. 6. Chitinous armature, top view: a, chitinous ring; i*^, outer teeth; c, inner 
teeth; d, triradiato jjharyugeal orifice; e, e, e, the ends of the (csoj^diageal 
rods. Four of the outer teeth have been removed to better show the inner 
row. A side view of this apparatus is i)rosented in Fig. 5. 

Fig. 6a. Top view of teeth. 

Fig. Go. Side view of teeth and basal support. 

Fig. 7. The bursa spread out : «, ventral rib ; b, ventre lateral; c, lateral; d, dorso- 
lateral; e, dorsal ; /, the eloacal orifice with two papilla' behind. 

Fig. 8. Spicula of male, composed of a chitinous tube surrounded by a membrane 
with a narrow wing. 

Fig. 8a. Portion of spiculum. 

Fig. y. Eggs: a, a, as they appear when deposited ; b, eggs in uterus. 

Fig. 10. Bursa of male, side view : a, a, a, ribs ; b, si>icuia ; c, c, anal papilke. 

Fig. 11. Head, top view: o, mouth; b, b, lateral papilke; c, one of the four acute 
jiapillu). 



PLSTE XXIV 



Tl -^^^3 



1,/ 



ten ] ci 



Q" 



Haines, del. 




CESOPHAGOSTOMA COLUMBIANUM 
(The Tumor-Making Uound Worm of Sheep.) 



17G 



(ESOPHAGOSTOMA COLUMBIANIJM, Curtice. 

I'LATK XXV. 

Fig. 1. Worm in third stage, XHO: a, head, with chitiiious armatnri-; b, u'sojyh.ign.s ; 
c,iute8tiue; rf, unicellular glands ; e,auu8; /, line denotiug uutural length. 

Fig. 2. Cephalic end, lateral view, Xl50 : a, chitinons cnp; b, one of the six cephalic 
papilhe, (these are slightly distorted) ; c, side view of the nock-fold, under 
which the gland-ducts d, d, open on the ventral line ; e, a^sophagus ; /, 
intestine. 

Fig. 3. Worm in first stage when 0.23'"'". long. No internal organs were seen in 
this specimen. 

Fig. 4. Cephalic end, ventral view : a, head ; h, ueck-fuld, near, which are the neck 
papilhe g, {/; c, cesophagus; d, d, unicellular glands, which open under tho 
fold b; e, intestine; /,/, glands. 

Fig. 5. Worm inclosed in its cyst. 

Fig. (I. Tumor from which the cyst in Fig. 5 was talieu : a, surrounding tissue dis- 
sected from cjBCum ; &, fluid-filled space ; c, capsule with inclosed worm. 

Fig. 7. Older tumor. This dili'ers from tumor of F'ig. 6, in having a movahle cheesy 
mass. These tumors are distorted by compression, which makes them too 
flat. Figs. 6 and 7, and Fig. 3, Plate XXVI, present three stages in the dis- 
ease, as seen in fresh tissues under low magnifying powers. 

Fig. 8. Section of an advanced tumor: a, mucous membrane ; h, submucous; c, inner 
muscular layer; d, outer: e, serous membrane; /, the cheesy mass of the 
tumor in which is a small section of the worm. This presents a more ad- 
vanced stage of the disease than Fig. 2, Plate XXVI. 



PLSTE XXV 








m 



Haines, del. 



CESOPHAGOSTOMA ('OLUMBIANUM 
(Young Stages.) 



178 



(ESOPITAGOSTOMA COLUMBIANUM, Curtice. 
Plate XXVI. 

Fi.i;. 1. A pit'ct) of uiucoiis meiiibraue taken from tliy caeiiiii, surface view, natural 
size. The |>atcli of dots scattered uniformly over the surface reprcseutH 
intestinal glands; the irregularly scattered larger dots aud elevationn arc 
the youug worm tumors in their lirst stages. 

Fig. 'i. A section through a worm tumor in its younger stage : a, a, a, mucous inem- 
braue ; h, submucous connective tissue, in which are c arteries and d veins ; 
e, the tumor, which is made of connective tissue cells aud their nuclei, 
packed closely together; near its center is the worm cavity/, with a piet;e 
of the worm, which is surrounded by a section of a special capsule; out- 
side of this is 11 thick membrane, formed from the surrounding material. 

Fig. :J. Small tumor dissected from the ciccum: a, the outside capsule tilled with 
lluid, in which is b, a hard, cheesy mass : c, the worm in its capsule, which 
has been pressed out of the cavity in the mass h. This presents a more 
advanced stage ol the disease than lig. 7, Plate xxv. 

Fig. :?a. The ruptured capsule. 

Fig. 'ib. The worm near the end of its second stage about to moujt. 



f 



PLHTE XXVI 



..-*.•*»' * 




So- .<#%^, 



r 




Haines, del. 



CESOPHAGOSTOMA COLUMBIANUM, 
(Small Tumors of Caecum.) 



A.Hoen & Co. lithocausticBaltiir 



180 



(ESOPIIAGOSTOMA COLUMBIANUM, Curtice. 
Plate XXVII. 

Fig. 1. Piece of c;t'cum exhibiting tumors caused hj tlio embryos of OLsophanostoma 
Colnmbianum, natural size. The various stages of growth are represented 
by the differeut sized tumois. The smallest are better shown in Plate 
XXVI, Fig. 1. 

Fig. 2. Cross-section of Fig. 1, at a a; b, mucous membrane; c, submucous; d, 
muscular and serous layers ; e e e, section through the cheesy masses. 



PLHTE XXVII 



\. 





di e «' 



Hai/nes, del. 



CESOPHAGOSTOMA COLUMBIANUM, 
(Large Tumors of Caecum.) 



A Hgen*Co,UthDC8UStic Bsir 



THE C^^CUM WORM. 
Trichocp:piialus affinis, Kud. 

Plate XXVIII. 

Descnption. — Male auil female about eiiual, 40 to 70'"™ 'oiig. Body whip-like, pos- 
sessing a short, stout caudal end, 12 to 18""" long, and a very thin liair-Iike cephalic 
end of twice this length. The latter contains the oesophagus and intestine; the 
fornuu' the reproductive organs and intestine. 

The head is very small and thin, without noticeable papilhe or chitinous armature. 
It is said to sometimes have two vesicular, transparent, wing-like intlatious. Skin 
of the neck transversely striate, and when highly magnified shows a serration of the 
sides indicating cuticular layers which overlap each other like shingles on a roof. 
CEsophj/gus and cephalic portion of intestine very minute ; its jiosterior end is large 
and dark, and empties at the caudal end of the body. On one side of the head there 
appears to be a canal filled with granules. 

Tlie male is to be distinguislied by its tightly-curled caudal end. The testicle, 
beginning near the cainlal end, continues anteriorly as a sinuous tube for about two- 
thirds the length of the thick portion of the worm ; it then becomes plaited to the 
end of the thick part, where it turns and continues posteriorly as an enlarged seminal 
duct for about half the length of the thickened body, where it is constricted; the 
remainder continues to the cloaca as a slightly enlarged tube. The intromitteut 
apparatus consists of two parts, an external membi'auous tube bristling with 8[)ine8 
and an internal long, slim spiculum. It is always found exserted, and usually has 
one coil in it. The tube shows at its end that the external covering continues 
around the end into the tube to form a lining membrane, which may be retracted or 
protruded. There is considerable space between these membranes at the tip, and it 
assumes various forms, varying between a large sphere, as shown in the figures, and 
an elongate cylindrical body. The chitinous spiculum is terminated by an acute 
point. It is from 5 to G'"™ long, with a width of 0,025""". The tube is about three 
or four times as wide. The spiny points are turned away from the end. 

The female has a thick body, only slightly curved. Tail, obtuse; ovary begins at 
the caudal end, continues as a plaited canal to the cephalic end of the thick part of 
body, theu contracting returns to the caudal end where it enlarges, forms a fold, .and 
becomes the uterus, which empties through the sinuous vagina and the vulva at the 
cephalic end, where the body begins to enlarge. Eggs characterized by having re- 
frangeut polar bodies at each end. They measure 0.077""" in length, including these 
bodies, or 0.056""" excluding them (Raillet). Tbey are elliptical and dark brown. 

Occurrence. — This spftcies is found in tlie ciecuni of sheep, goats, and 

cattle. When the fresh intestine is examined the worm may be found 

with its slim, hair-like head firmly sewed into the raucous membranes. 

The serrated structure of the skin not only facilitates the progress of the 

head through the mucosa, but prevents ifs being i)ulled backward. The 

thick large end, which is wh;it one really sl'cs at first, appears to float 

free iu the intestinal contents. 

181 



182 

The life history of this species has been determined by Leuckart, the 
distinguished helminthologist, who has added so much to this branch of 
biology. He succeeded in raising young embryos from the eggs to such 
a stage that there was no reasonable doubt that the next stage was passed 
in sheep. These he fed to a lamb, which he killed after sixteen days. 
In these he found numerous immature trichocephaU ahontl""" in length. 
He later verilied this experiment by another, with like results. {Die 
menschlichen Parasiien, Band II, 494:-4:99.) 

These experiments show that the eggs of Trichocejyhalns affinis, which 
pass from sheep to the ground, may develop there to some degree, and 
then, after being consumed with food or drink by a second sheep, con- 
tinue their development to their adult stages. 

Disease and treatment. — Unless the parasite should be ])resent in great 
abundance the species does not seem to be especially harmful. A few 
may be found in nearly all lambs and young sheep, especially in the 
all. The means of prevention is just the same as for other round 
worms. As they are attached so stoutly to the mucous membrane it is 
doubtful whether medicinal remedies would have the influence on them 
that they have on those worms situated in the small intestine. 



184 



TRICHOCEPHALUS AFFIMS, Rndolphi. 
Pl.ATK XXVI II. 

Fig. 1. Piece of cpecuin with tricltocephali attached, natural size: a, a, females; h,h, 

males. 
Fig. 2. Male, x7: rt, ca))illary cephalic end ; /^, coihul caudal end ; c, protriid«Hl inlm- 

mittent organ ; d, the convoluted, and e, the straight portion of the seminal 

apparatus; /, seminal reservoir; </, intestine. 
Fig. 3. Female, x7 : a, capillary cephalic end; /;, vulva; c, vagina; d, uterus; e, 

oviduct; /, convoluted ovai'y; g, intestine. 
Fig. 4. Caudal end of male enlarged : a, end of the body; &, spine-covered tube of 

intromitteut organ ; c, its inflated end ; d, spiculum. 
Fig. .'}. Cross section of end showing how the outside sheath becomes converted into 

the inside sheath of the tube : a, a, the sheath ; h, the sac formed ; c, the 

hollow spiculum. 
Fig. G. End of sheath, much enlarged, to show the relation between sheath and 

spiculum. 
Fig. 7. The head. 

Fig. 8. The vulva and vagina, with an egg in the passage. 
Fig. 9. Eggs: a, eggs without .*«li(dls ; /;, egg with shell and its characteristic polar 

bodies; c, intermediate between « and h. 
Fig. 10. Enlarged portion of worm from near the head. 



PLSTE XXVIII 




Geo. Marx, dtl. 



TRICH0CEPHALU8 AFFINIS, 
(The Hair-headed Round Worm.) 



LUNG WORM DISEASES -PAPER SKIN, HOOSE, HUSK. 
Verminous Pneumonia — Verminous Bronchitis. 

Platos XXIX to XXXVI. 

The lung worms which cause disease iu slieep in the United States be- 
long- to two, perhaps three, different species. They are Strongylusovis- 
pulmonalis, Diesing, the liair lung worm ; and Strongylus Jilaria, Rud., 
the thread lung worm. The third species, which has been reported as 
infesting sheep in Europe, is the hog lung worm, IStronfiylus paradoxus^ 
an abundant species occurring in the lungs of swine ia this country, 
and while ithas never been credited as having been found in our sheep 
it is to be looked for. As its size and the disease it causes is similar to 
that oi Strongylus Jilaria, it will not be treated separately. 

The diseases produced by these species of worms are caused by the 
mechanical injuries the worms intlict on the delicate merabraues of the 
lungs and the clogging up of the air passages by them and the debris 
which they i)roduce. The two forms of disease produced depends on the 
different size and habits of the two species. Strongylus ovis-pulmonalis, 
being very small, penetrates the air passages to their endings iu the 
bronchioles and infundibuli, and causes disease in them primarily, 
while Strongylus Jilaria, which penetrates only into the bronchi, creates 
a disturbance there which produces a solidification of the luug second- 
arily. The general diagnosis of each disease is no easy matter. The 
disease produced by Strongylus ovispulmonalis is characterized by the 
spongy feeling of the lung and the presence of nodules from the size of 
a mustard seed to that of a pea scattered under the surface of the dor- 
sum of the lung and at its posterior free edge. These may be connected 
by agrayish, fleshy, intermediate portion of the lung into patches of con- 
siderable size. The parasites can scarcely be seen by the unaided eye; 
but if small pieces of the affected lung or a tubercle be placed in a shal- 
low dish of water and teased out with needles under a tripod lens, they 
can be readily seen. 

The disease produced by Stro7iglyus Jilaria and S. paradoxus is char 
acterized by the posterior i)ortion usually, or some entire section of the 
affected lung appearing as a solid, usually red, mass which has lost all 
of its contained air and is in a state of hepatization. A piece cut out 
generally sinks in water, while pieces from the former disease float. If 
in the latter disease the trachea is carefully slit open and the branches 

185 



186 

traced down to tho, affected part the parasites will be found in thread- 
like bunches, completely tilling the tubes. 

The sytnptonis of lung- worm disease in sheep can not well be diag- 
nosed in living animals unless the disease is far advanced, and then 
only in the severer cases. Sheep affected with either disease generidly 
have pale, bloodless mucous membranes, harsh, dry hair, a dejected 
look, more or less difficulty in breathing, and often a deep cough. The 
bloodless condition of the sheep could arise from other parasitic 
troubles, but the disturbance of respiration should lead one to suspect 
lung i)arasites. 

Consumption or tuberculosis is apparently a rare disease in sheep, 
and is not liable to be confused with this disease, which can always be 
diagnosed by finding the parasite. Lung- worm disease differs from 
acute bronchitis or pneumonia in being of slow development, and is less 
severe in its symptoms. Worm diseases consume weeks in develop- 
ment, while acute tliseases are begun and finished in a few days. 

THE HAIR LUNG WORM-VERMINOUS PNEUMONIA. 
Stronoylus ovis pulmonalis, Diesing. 

Plates XXIX, XXX, XXXI, XXXII, XXXIII. 

Description.— M&\e, IG"""; female, 2b<"'"; vvicltb, male, O.f)"'"' ; female, 0.17'""'. Cap- 
illary iutegument of worm very transparent, the cavity of the body appearing as a 
dark line. Head not winged ; fonr papiihe ; month naked. Male, bursa pointed, 
compressed, terminal; costie (apparently) seven ; one posterior; twice-notched ; two 
pair lateral, one pair anterior ; spicula symmetrical, spatulate, curved; 0.15""" long, 
divided into two nearly equal parts; the anterior consisting of a cylindrical cbitinoua 
skeleton with a membraneous expansion, the posterior of a transversely ribbed skele- 
ton, margined by a thin broad curved membrane, the two spicula forming a partially 
closed tube. Female oviparous, with two uteri and ovaries. The former empty into 
a vagina at 0.8""" from vulva. Vulva 0.1""" from auus. Anus 0.08""" from tip of 
tail. Tail ends in a blunt point. Eggs in uteri 0.1'"'" long, 0.04""" wide. The eggs 
segment after being laid. Embryo provided with a very sharp-pointed tail. 

Life history. — The young of the hair-lung worms escape from the lungs 
of infected sheep and become scattered over the pastures, yards, and 
other places freciuented by these animals. They are then taken with 
the food or drink and in some way arrive in the lungs of the sheep. 
Arriving at the extreme ends of the bronchial tubes, they break down 
some of the tissues and become encysted. In the cyst they grow to 
adult size and take on .sexual characteristics. Escaping from the cysts 
they niake their way into the snuill air-tubes (bronchioles and bronchi), 
where the sexes mate and reproduce. The eggs are then laid in sur- 
rounding cavities and hatched into young worms, which make their way 
into the neighboring air-chambers (infundibula). Afterwards some of 
these worms may be coughed out of the lungs onto the pastures and in- 
fect other sheep. 

In their life history there are but one or two points about which there 
can be any question. Many learned helminthologists believe that the 



187 

young worm must escape from the sheep in order to spend a portion of 
its life on tlie ground or in some of the minute forms of animals before 
they are capable of further develoi)meut in the sheep. Most authors 
are agreed that the worm passes into the lungs by the trachea either 
during feeding or rumination. The length of time which it takes the 
worm to complete its cycle of life is yet unknown. As the most pro- 
nounced cases among slaughtered animals are in the older sheep, it would 
seem as though this parasite was of very slow growth, requiring years 
instead of months for successive generations to produce a disease fatal 
to the infested sheep. It may be, however, that many lambs and 
young sheep are so seriously affected with the i)arasite that they either 
•die or become so inferior in quality that they are never taken to the 
abattoir. In this case the cycle of life would i)rove to be rapid. 

Disease. — The diagnosis of verminous i)neumonia in living animals 
is a difficult matter. Not until the disease is so far advanced that its 
cure is hopeless are any well-pronounced symptoms developed. The 
worst affected sheep may have a deep cough, be out of condition, and 
be generally anaemic, as shown by the pallor of the visible mucous mem- 
brane and the dry, harsh coat. They are likely to lose flesh, but some, 
if not seriously affected, fatten tolerably well. 

The post mortem diagnosis is as certain and definite as the diagnosis 
in life is unsatisfactory. So j)ronounced are the lesions caused by the 
worms in the lung tissue that any one having once seen a diseased 
lung would easily recognize it again. The little tubercles, tilled with 
greenish material and surrounded by more or less of the thickened 
lung tissue which when cut exudes a frothy liquid, are diagnostic. 
The presence of the worm in these tubercles is decisive. 

The prognosis of this disease can not be deiinitely given. From many 
examinations of affected lungs it seems to me that the disease is a pro- 
gressive one, producing its worst effects as the sheep grow old. Where 
the sheep are marketed young the loss from this parasite is compara- 
tively small ; but where the disease is wide-spread and affects whole 
flocks, though but a few cents may be lost per head, the aggregate loss 
to the sheep industry must be considerable. To this must be added the 
loss from the disease in its more severe stages. When the disease is 
once in a flock and the farm or range is infected with it there will be a 
steady loss resulting until the disease is in some way exterminated. 

Pathology. — The disease created is dependent upon the life history of 
the parasite as to character and upon the numbers of the invading hosts 
for its intensity. The changes produced in the lungs are but the aggre 
gate of all the changes which result from the different invading individ- 
uals, and the history of the changes wrought by a single parasite illus- 
trates the changes pioduced by all. The minute worm, when entering, 
penetrates the air passages to their extremities. In the u.ltinuite alveoli 
it breaks down some portion of the membranous partition and becomes 
surrounded by the products of the inflammation which it excites and 



188 

foruisavcry minute tubercle. When this tubercle has rea(;lied from one to 
two and one-half niillinieters (ouetwenty-lifth to one-tenth of an inch) in 
size, it is composed of a distinct central part, tilled with a soft, greenish, 
central portion, which is surrounded by a thicker membranous capsular 
portion, coniposed of cells of new growth, the inner i)art of which degen- 
erates later and enters into the formation of the cheesy central mass. 
Within this tubercle is the young i)arasite. In later stages this tubercle 
enlarges until it becomes 3"'"' in diameter. In this stage the soft interior 
mass will be firmer. The parasite is always found between the interior 
mass and the capsule, and is surrounded by the soft, freshly-formed 
greenish material, which it seems to produce by the irritation of the 
adjacent capsule. When the parasite attains its adult size it evidently 
breaks from the tubercle and thereafter lives in the adjacent bronchioles. 
There is quite a difference in the external appearance of the little tuber- 
cles during the different stages of growth. In the earlier stages they 
appear as little blood-red spots just beneath the pleural coat of the 
lung ; later they look like little brownish tluid-tilled tumors, surrounded 
by a red zone; still later a yellowish, green, (;heesy material api)oars in 
their center, and the tumors present a greenish gray ai)pearance. The 
gray is due to the thickened capsule and a thickening of the pleural 
coat of the lung over the little tubercle. There is usually a slight ele- 
vation of the surface of the lung over these nodules, but this feature is 
dependent on the depth at which the nodule is situated. They may 
occur at any depth in the lung substance, but are usually near the sur- 
face. When the parasite escapes from the nodule a new phase of the 
disease begins. It wanders through the bronchi until it meets one of 
the opposite sex, when they mate. Soon after the female begins to lay 
eggs in the bronchioles and alveoli, which she infests, and these eggs 
in turn hatch into young worms. These young worms are very lively, 
and help to increase the disturbance of vital functions of the lung sur- 
rounding them. That part of the lung then becomes as if sodden, the 
air tubes fill with eggs, worms, cast-off epithelial cells, mucus, wan- 
dering cells, and air globules; the tissues of the walls of the alveoli 
become thickened and encroach upon the contents, and the function of 
the i)art is entirely suspended. The effect of the worm and its brood 
at this stage is to |>roduce a pneumonia, hence the disease has been 
termed verminous pneumonia. This pneumonia is limited to the neigh- 
borhood of the parasite and does not extend beyond. The patches are 
irom 1 to 2.5"" in width, but in those recently formed they rarely ex- 
tend more than 2 or 3""" deep. The injury seems to be mainly a me- 
chanical effect, due to the irritation set up by the parasites. When 
one of these patches is cut into \i frothy liquid exudes, bearing quanti- 
ties of eggs and embryos in all stages of development. They may be 
seen with a glass magnifying six diameters. 

In later stages of the disease the tubercles become little hard masses. 
These have been said to be calcareous, but they arc not soluble in acid, 



189 

aud seeni rather to be tlie contracted, hardened remains of the cheesy 
mass. There are sometimes found in certain lungs raised patches of a 
rather dry, emphysematous tissue, whicli seems to be due to the deeper 
lying parasites. In other lungs the patches which once showed the 
pneumonia have becoiued thickened, tirmer, denser, and a cut across 
them shows the thickening to extend to a considerable depth. 

The abundance of the nodules and patches of i)neumonia is very vari- 
able. There may be a dozen nodules of different sizes and two or three 
patches, or the nodules may be diffusely scattered over the whole pos- 
terior surfaces of the lung, or there may be associated with tliem numbers 
of patches due in part to the close proximity of the nodules and in part 
to the extension of the disease. In other cases there may be a few of 
the nodules with a series of patches ranged along the dorsum of the 
lung. Each lung seems to present a slightly different phase, dependent 
on the degree and the time of infection and possible reinfection. 

Source of infection. — That verminous pneumonia is caused by a worm 
(Strongylus ovis-piilmonaUs) and that sheep become infested while feed- 
ing or drinking has Already been enlarged upon. It is obvious, there- 
fore, that the best way to keep the sheep well is in some way to i)re- 
vent them from becoming infected with the parasite while feeding. 

Preventive treatment. ~\n giving rules for prevention the value of 
knowing the complete life history is fully illustrated. The unexplained 
gaps in this history are two, viz : there has been uo complete demonstra- 
tion of the manner and place in which the parasite spends its life be- 
tween the time of its escape from the lung of one animal and its recep. 
tion into that of another, nor has it been demonstrated that the worm 
must escape from the lung before it may complete its development. 
This latter item is an important one, for if the worms can continue 
multiplying indefinitely in the lung then there is little hope of freeing 
a sheep after it is once infected. On the other hand, if an infected 
sheep is to be regarded as incapable of continuing the infection within 
itself then the case is more hopeful. If the parasite must become para- 
sitic on a second host while external to the shee]>, as some claim, this 
is an important factor in its life history, for its continuance then depends 
on the presence, abundance, and seasonal appearance of this second 
host, and influences adverse to the life of the second host would be un- 
favorable to the parasite. 

As the parasites are present in the lungs of sheep throughout the 
year in all stages, this theory does not seem to hold good. The infec- 
tion of lambs is proof enough that the parasites are continually passing 
from one sheep to another, and whatever be the mode of living there 
are certain precautions which may be taken to keep the sheej) less in- 
fected if not to entirely exclude the worms. The older sheep, which 
seem to be more infected and which are the source of infection for young 
ones, should be marketed. Lambs should be weaned as early as they 
safely can be, separated froni the older sheep, pastured in fields where 



190 

there have been no sheep since the previous winter at least, and never 
allowed to pasture, water, or yard after infected animals. 

Sheep should be supplied with water from running streams or trou^Mis, 
and should not be allowed to contaminate the water in any way. Filthy 
drinking water is one of the most prolific sources of the parasite. 

There are two kinds of seasons which especially favor the production 
of parasitic diseases. The one is a very wet, warm season, during which 
the parasites seem to be able to live on the damp ground. The other 
is a very dry season, when the i)ools of water become diminished and 
(Stagnant, and whatever parasitic eggs or embryos there are in them are 
gathered into so small a volume of litpiid that sheep drinking of the 
water become more readilj' infected. Wet, <lamp pastures, and pastures 
with puddles in them are alike favorable to the worm diseases. Sheep 
should be excluded from such i)laces as much as possible. 

A constant watch of the condition of the lungs in dead and slaugh- 
tered sheep will enable the flockmaster to judge of the progress that 
his care in preventing the disease has made. ^ 

Medicinal treatment. — There is no medicinal treatment that can be 
profitably followed. Salting, grain-feeding, and healthful surroundings 
are required not only to keep up the health of tlie animal for the pro- 
duction of wool but to tit it for the market, which is the best phice for 
seriously aflected sheep. 



192 



STRONG YLUS OVIS-PULMONALIS, Diesing. 
Plate XXIX. 

Fig. 1. Cephalic eud: «, <i'.s<)i>hagiis; b, intestiue. 

Fig. 2. Head with papillji'. 

Fig. ;{. Caudal end of female: a, amis; b, vulva; c, vagiua; d, d, uteri ; e, e, ovi- 
ducts; /, /, ova; g, g, iutestine. 

Fig. 4. Middle of female with tail of male coiled around her. 

Fig. 5. Spiculum: a, cyliudrical part of the skeleton; 6, spatulate ribbed i)art ; c, 
wing of tube: d, membranous tip. 

Fig. 0. Spicula as they fit together. 

Fig. 7. Adult male and feuuile, Xfi. 

Fig. 8. Caudal eud of male: a, spicula. 

Fig. 9. Male bursa with apiuessed cost;e. 

Fig. 10. Male bursa with separated costa-. and sjticula in situ. 

Fig. ll. Caudal end of female, lettered as in Fig. ^5. 



PLSTE XXIX 




Haines, del 



A.Hoen & Co. Lifti. Baltiii 



STRONGYLUS OVIS-PULMQNALIS 
'The Hair Lung Worm.) 



194 



STRONGYLUS OVIS-PULMONALIS, Diesiug. 

Plate XXX. 

Portion of left luug slightly affected by the stroiigyli. The purplish spots are those 
more recently invaded. The small gray spots are older. The large gray spots are 
caused by the worms and their young, which have produced an appearance of local 
pneumonia. 



PLATE XXX 





llalnea, del. 



SURFACE OF LUNG RECENTLY INVADED BY STRONGYLUS OVItJ-PULMONALIS. 



196 



STRONGYLUS OVIS-PULMONALIS, Diesing. 

Platk XXXI. 

Left Inng diseased by Slrongyhis ovis-puhnonalis, the hair lung-woriu. Natural 
size. Each dot is caused by the irritation set up by a young worm, aud its size cor- 
responds to the age of the worm. The larger patches consist at first of separate 
dots; as these enhirge they run together and finally become so fused that their 
identity is lost. The patches show the stage at which the worms become adult aud 
produce their young, which wander into the adjacent air cavities. 



PLKTE XXXI 






i" 




Haines, del. 



'■Is.. S 



SLTRKACK OF LUNG l)|SEASEI> BY STKONGYLUS OVIS-PULMONALIS. 



198 



STRONGYLUS OVIS-PULMONALIS, Diesing. 

Plate XXXII. 

Portion of right lung, oxhibitiug an advauced stage of the hair lung-worm disease. 
The small dark spots show the youngest stages, the large patches show the disease 
well advanced, while the largo light spots are the oldest. A section cut across one 
of these shows the depth at which the lung is atfected. 



PLSTE XXXII 



1. 




% 



Haines, del. 



A.HaBriir.D.Lithocsiistiu.Baltin 



SURFACE OF LUNG DISEASED BY STR0NGYLU8 OVIS-PULMONALIS. 



200 



STRONGYLTIS OVIS-rULMONALIS, Diesing. 
Plate XXXIII. 

Fig. 1. Section of lung tissue through two small tumors caused by the worms X20: 
a, caseous degeneration of tissue in the center of the tumor ; b, the same 
in the pathway of the moving, growing worm; c, cut fragments of the worm 
(the pathway of the worm is interrupted between a and b, because the plane 
of the section did not include it) ; d, a bronchus into which the parasite has 
almost found its way; e, portion of a second tumor made by another worm; 
/, nearly normal tissue. 

Fig. 2. Section through an older tumor at the stage which has been likened to pneu- 
monia, X20: a, tumor with fragments of worms; b, fragments of an adult 
worm ; c, eggs in segmentation stage ; d, embryos somewhat developed ; e, 
young embryos; /, bronchi; g, nearly normal tissue. 

Fig. 3. An enlargement of b, Fig. 2, .showing fragments of adult worm in the bron- 
chi and alveola). 

Fig. 4. An enlargement of e, Fig. 2, showing young worms in the alveohc. 

Fig. 5. An enlargement of c, showing segmenting eggs in alveoli. 

Fig. 6. An enlargement of d, showingd eveloping embryos in alveoli. In Figs. 5 and 
G the outlines of the egg-shells are not shown. Figs. 3-6, X90. 
(These illustrations were made from specimens selected from a number of serial 
sections which were stained with alum-carmine; the dots represent the 
nuclei of the cells. All sections show the great multiplication of cells 
about the points of irritation, whether excited by the adults or embryos.) 

Fig. 7. o, embryo of Stronfinlus fdaria, and b embryo of S. ovis-puhnonaUs, each equally 
enlarged to show comparative differences in size and outline. 



PLSTE XXXIIl 



^: 













-,a««--,<,;'\r , 






:m-.^ 



;;^ 






Haines, del. 




m' 



SECTIONS OF LUNG DISEASED BY STRONGYLUS OVIS-PULMONALIS. 



THE THREAD LUNG-WORM-VERMINOUS BRONCHITIS- 
HUSK OR HOOSE-PAPER SKIN. 

Steongylus filakia, End. 

Plates XXXIV, XXXV, XXXVI. 

The thread liiuj? worm, or Strongylus Jilaria, is the best known of the 
sheep lung worms, for the reason that at times it causes exteusive epi- 
zootics in the iiocks, and that the worm is hirge enough to see when the 
bronchial tubes are slit and spread open. From personal observation 
it appears to be much rarer than Strongylus ovis-pulmonalis, and the 
disease it causes much less extensively distributed as to number of 
animals infected than that produced by the latter. In most of the 
American literature on this subject the disease caused by the hair lung- 
worm seems to be ascribed to the thread lung worm, and no mention is 
made of the former. 

Description.— M.a,\e, 33 to 54""" ; female, 55 to 80™". Worm filiform, white, with 
a dark hair line showing throughout its length; head obtuse, without notice- 
able papilhe or wings ; mouth circular, naked ; unicellular neck glands quite large ; 
cuticle longitudinally striate. Male : Bursa shallow, canipanulate, opening later- 
ally ; fiv-e sets of costie ; the dorsal are trifid, the lateral bifid, and the ventral sepa- 
rated. Spicula arcuate cylindrical ; 3.35""" long by 0.07.5""" wide ; short, very 
tliick, dark brown; chitinous portion a curved fenestrated conical tube; fleshy por- 
tion a membrane, which forms a bulb-like expansion toward their free end. Female : 
Vulva three-sevenths of her length from the head; uteri symmetrically directed 
anteriorly and posteriorly ; posterior oviduct becoming continuous with the uterus 
near its flexure at the tail; ovo-viviparous; eggs ellipsoid, 0.075 to 0.120™"" long; 
0.045 to 0.082™™ wide. Embryo 0.25 to 3""". 

The life history of Strongylm filaria is in general that of other para- 
sites. In some way the young worms arrive in the bronchi, grow, de- 
velop, become adult, mate, and lay their eggs in the surrounding mucus. 
The eggs laid are not true eggs, for each egg-shell contains a j'^oung 
worm within, a feature which is described by calling the female ovo- 
viviparous. The inclosed young escape from the shell, and many of 
them are expelled from the lungs in the coughing fits along with other 
discharges. These young, which are scattered about watering-places, 
pastures, sheep-yards, or corrals serve as infecting and reinfecting ma- 
terial for a considerable length of time. Professor Leuckart {Entwickel 
ung d. Nematoden, Arch. d. w. MeilJcunde, 1865, p. 299), kept the young 
of this species alive for several weeks on damp earth, and observed them 
pass through a stage in which they molted or threw off their skins, 

201 



202 

after which many died. Baillet {GoUn, 0., Bull deVAcad. dc Med., t. 
XXXI, 18G0, p. 874) preserved them alive in water for several mouths. 
Ercolani {Ncimiann, Traitc des Maladies parasitaires, p. 515) is author- 
ity for the statement that they can be resuscitated after being dried a 
year by putting them in water. The writer has kept them in stagnant 
water for weeks. Ercolani's statement is by far the most remarkable, 
and accounts for results obtained in an experiment in which the writer 
kept sheep for five months on a narrow dry pasture, supplying them 
with water from a pump only. When these sheep were examined they 
were found affected with Strongylus contortus, S.Jilicollis, iS. ventricosusy 
Dochmiuscermius, and Tcenia expansa in very young and old stages. The 
eggs of these were introduced on the pasture from two or three older 
sheep which were with the younger ones, or possibly by the young 
sheep themselves, some of which were between three and four months 
old at the time. Two of the lot were born and raised under experi- 
mental supervision, and these were also infected. Strongylus Jilaria 
was not present, but it was not discovered in any of the sheep from the 
same lot killed at the time of selection of the experimental animals, nor 
has any trace of this parasite been discovered in any of the older ones 
kept at the Experimental Station. 

Professor Raillet details experiments {Recueil de Med. V^terinaire An- 
ne.re, 7 Serie, Tome VI, No. 8, April 30, 1889, p. 173) in which he dried 
embryos of Strongylus Jilaria under different conditions, and found, after 
a few failures, that some could be revivified as late as sixty-three hours 
afterward by placing them in water. His success depended on the 
condition of the embryo at the time of drying. 

It may be accepted, therefore, that the young parasite may retain vi- 
tality indefinitely, depending on telluric and atmospheric conditions. 
From Leuckart's experiment it is to be inferred that though moist earth 
and damp places are favorable for the life of the young parasites, yet 
they are liable to molt and then may die from the loss of the older and 
tougher external skin. From Ercolani's and Raillet's experiments we 
may infer that the drying of the young parasite suspends its functions, 
which revive again when the surroundings are suitable, .and that the 
parasite is in this state the most dangerous to sheep. 

Preventive treatment. — The foregoing indicates that after a farm is 
once infected the prevention is not an easy matter, for dry embryos 
may be scattered everywhere. Although the parasite is more abundant 
at some seasons than at others, yet it may be found in limited numbers 
at all seasons, and animals aflected will distribute the eggs throughout 
the year, thus increasing the diflSculties of prevention. All animals 
wliich show the least appearance of being affected should be separated 
from the sound ones. The water supplied to the sheep should be pure, 
i.e., either taken from wells or led into troughs from sources which can 
not be contaminated. If the sheep are allowed to drink from running 
water, then all of the brook should be fenced out except where the 



203 

sheep drink. Dry pastures without bog-holes or sloughs are best for 
the animals. As the germs live for some time in a dried condition the 
old pastures should not be used for young sheep at least, nor should 
the latter bo allowed to graze after older sheep which have had the dis- 
ease during the previous year, nor should the pasture be overstocked 
so that the grass is eaten to its roots. 

Disease. — Verminous bronchitis attacks young animals, those under 
two years being the more susceptible. Animals poorly nourished and 
those already weak from other parasitic diseases are also more liable to 
become a prey to this worn. Damp, warm seasons are most favorable 
for the preservation of the parasite and the disease it produces. The 
disease is most prevalent in summer and autumn, becomes less in 
winter, and disappears in spring time. 

The symptoms of this disease, as in verminous pneumonia, are im- 
perceptible in the first stages. It is probable that, beyond the slight 
but deep cough produced in some of the worst cases, but little else can 
be noticed. The sheep may have difficulty in breathing when driven 
or be short-winded. They may be aucnemic, as shown by the harsh, dry 
skin, dry wool, and pale mucous membranes. In later stages the 
symptoms will be aggravated; difficulty in breathing, coughing, and 
general debility, associated with an anaimic condition, will be the most 
prominent symptoms. Occasionally shreddy masses will be coughed 
up, which, on close examination, will prove to be worms. This is a 
decisive test of the nature of the disease. 

The sheep has a fair appetite, but will gradually lose flesh. In the 
last stages the bronchial cartarrh is severe, the respiration very feeble 
and jerky, the cough deep, convulsive, and evidently painful, coming 
by fits and followed by suftbcation, which leaves the patient still more 
exhausted. The nasal discharge becomes more copious, and contains 
quantities of embryo and worm fragments. Owing to the diminished 
respiration productive of anaimia, the skin becomes dry and harsh, and 
resembles parchment ; hence the popular name " paper-skin." The wool 
is also affected and is easily ])ulled oft", exposing the white, bloodless 
skin underneath. 

Duration. — Death occurs in three or four months either by exhaus- 
tion of vital forces or by suffocation. As the first stages pass unnoticed 
the total time from infection to death is probably nearer five or six 
months. The duration of the disease depends on the amount of infec- 
tion, the previous health of the patient, the care it receives, and its vi- 
tality. Where the symptoms are very decided the patients rarely sur- 
vive. The disease is most intense in autumn, and if the sheep do not 
die, it becomes less intense in winter to more or less completely disap- 
pear in sirring. When the season has favored the development of the 
disease and the lambs show severe symptoms, the outlook for their re- 
covery is very unfavorable. A large percentage of those attacked die. 



204 

Others fall away in flesh to a serious extent and the growth of the fleece 
is retarded. 

Occurrence. — It is a usual thing to find lungs aft'ected with Strongylus 
ovis pulmonalis^ and more rare to And them aflected with IS. Jllaria. 
When the latter occurs it is ordinarily associated with the former, 
owing to its abundance, but it is easy to separate the two diseases. In 
the beginning of the S.filaria disease the very posterior tip of the lung 
is affected, turns dark red or grayish, and has a solid feeling and ap- 
pearance. From this the disease spreads anteriorly, lobe after lobe 
of the lung becoming involved as the bronchi choke up. These termi- 
nal patches are very sharply separated from the adjacent portion of the 
lung, which appears normal, except that it may be infected with S. ovis- 
pulmonalis, as indeed may be the part infected by S.Jilaria. The cause 
of this solidification or hepatization (so called because it becomes solid 
like liver) is the stoppage of the air tubes by the worms and the debris 
they produce. When they exclude the air from the part the air cells 
fill with debris and the part becomes solid. Portions of Jobes elsewhere 
may become involved, but more rarely. The anterior lobes often ap- 
pear red and solid, but it will generally be noticed that in these the red 
part is thin and not as spongy and resistant as the lobes in the poste- 
rior end. This state is due to the air being driven oat of the lobes and 
the walls coming together, producing a state of collapse (caruification 
or atelectasis). 

The solid lung produced by S.Jilariais often covered by a thickened 
whitish membrane, the inflamed serous membrane, which often grows 
fast to the chest or thoracic walls. After the worms disapi)ear, eitber 
having been killed by remedies or from some unknown reason, the heal- 
ing i)rocess begins, and the lamb recovers if not too much weakened. 

Treatment of this disease is far more hopeful than that of the pneu- 
monia due to Strongylus ovis-pnlmonalis. It may be dietetic, preventive, 
and medicinal. In an essay on this disease Mr. Stephen Powers {The 
American Merinp, O. Judd Co., 1887, p. 283) says : 

To sustain the strength and vitcality of a sheep already affected is exceedingly difli- 
cult, because the appetite is feeble and capricious. Tlio lamb can seldom be induced 
to eat enough even of the most nutritious food, to make any considerable impression 
on it in the way of betterment ; and the danger in giving it by force stimulating 
gruels, etc., is that, owing to its bloodless condition, the process of digestion will be 
HO illy performed that the food will do it more harm than good by causing scours. 
High feeding is of transcendent importance as a preventive measure; l)ut when tlie 
lamb has reached such a pass that vermifuges have to be employed, it is necessary to 
proceed with great caution in giving rich food. 

These remarks commend themselves to all who have had experience 
with afflicted sheep. Keep the lambs up to the highest point of ex- 
cellence and health by feeding and they will the better withstand the 
ravages of the parasites. Corn and oats, bran, chops, and oil-cake are 
all good fatteuers, and should be given in i)roper proportions. Salt 
should be placed where the sheep have free access, not only as a diet- 



205 

ary article, but for its medicinal iuflueuce. In addition they should 
have pure, fresh water once or twice a day. Wlieu the animals have 
become sick good diet should be supplied. As intimated by Mr. Powers, 
those animals which seem most in need of food take the least, and if 
they do eat i^.may even be of harm to them. However desirable it may 
be to feed animals well as a hygienic measure, still no amount of feed- 
ing will keep them from being infected when a season favorable to 
the parasite appears. There must therefore be a continual diligence 
exercised in keeping the pastures in good condition and the young 
sheep especially from becoming infected. As the parasites seem to thri ve 
best in water, it follows that dry pastures should be preferred. The 
danger of infection from pastures should be diminished by limiting the 
number of sheep, so that they will not have to eat the grass close to 
the roots, and by a judicious distribution of the young sheep on practi- 
cally virgin pastures. Should a pasture have become permanently in- 
fected from long use it should be plowed up and either cultivated a 
year or two or allowed to stand idle or surrendered to other stock. 
The effect of the cold upon the embryos of these parasites is not yet 
known, and it may be that the alternate freezing and thawing which 
they sustain is in the Northern States the cause of the destruction of 
large numbers of them. Leuckart's experiment of keeping the wo^ms 
in moist earth, during which time many molted and died, indicate 
that a pasture would be much safer w^hen thoroughly dried after a pro- 
longed rain than before, and also that such a wet time would be more 
dangerous for the sheep. A judicious selection of pasturage through- 
out the year, together with a shifting of the sheep from pasture to past- 
ure as the season and ages of the sheep seem to require, is the best 
that can be counseled at present. 

MeMcinal treatment may be productive of much good, but is usually 
resorted to so late that its best effects are lost. Medicines haye been 
administered with the food by drenching, by fumigations, and by 
tracheal injections. Salt and copperas in proportions of from 1 of cop- 
peras to 25 of salt, and of 1 of copperas to 4 of salt, the last mixture 
being given in wet weather, has been advised {The American Me- 
rino, by Powers, 1887, p. 285). The weaker mixtures maybe kept con- 
stantly bejfore the lambs for eighteen months. The stronger should be 
alternated every two or three weeks with clear salt. Powers kept it 
constantly before the lambs until after the second summer. I would 
deprecate the use of copperas for any continued length of time, for it 
not only harms the teeth, but if persisted in loses its force as a tonic 
remedy. In administering dry medicines in food much of their force is 
lost, for they are very apt to accumulate in the paunch or first stomach. 
Medicines given by drenching are more expensive in the dosing but 
more effective, for small quantities of fluids pass directly into the mani- 
folds or third stomach, and thence into the fourth stomach, especially 
if the sheep be thirsty. But few of the many remedies advised are in 



206 

the least effective except they be general tonics aud stimulants. Many 
advise the use of anthelmintics, but these are of vahie only in driving 
oft" the intestinal parasites. Turpentine seems to be an exception to 
this rule, as some of it is eliminated by the lungs and so reaches the 
worms. Powers {op. ciL, p. 283) advises turpentine and linseed oil mixed 
in equal parts, a tablespoonful at a dose. Mr. W. G. Berry saturates 
lumps of salt with turpentine, then crushes the salt, mixes with bran, 
and feeds as a preventive. 

Neumann {Maladies Farasitaires, p. 517) states that the following 
have been recommended : Picrate of potash, from 3 to G grains per dose, 
dissolved in oatmeal, water, or mucilage; a mixture of equal parts of 
turpentine and spirits of camphor, a teaspoouful daily in mucilaginous 
drink ; a mixture of creosote 120 parts, alcohol 500 parts, water 700 
parts, dose a teaspoonful ; creosote GO parts, benzine 300 parts, water 
2,000 parts, dose a teaspoonful for each patient daily for eight days* 
Hall {Veterinarian^ 18G8) says that he employed with success 10 drops 
prussic acid (to be diluted in water) for a dose morning and evening. 
Neumann adds, however, that experience shows there is little reliance 
on these methods of treatment, and the administration is, besides, more 
or less difficult. 

The same author states that success is less uncertain with fumiga- 
tions which penetrate directly to the worms, benumbs them, and pro- 
vokes a cough by which they are brought up and ejected. The shee[) 
to be treated should be driven into as nearly an air tight shed or stable 
as is practicable. Then rags, horns, feathers, hair, old leather, tar, 
asafetida, etc., should be placed on a red-hot shovel or in an iron pot 
filled with burning coals or in a tinner's fire-pot. The intensity, dura- 
tion, aud number of fumigations should be graduated according to the 
tolerance of the sheep. Either some person should subject themselves 
to the same fumigations, or a very close watch should be maintained in 
order to prevent the lambs suffocating. 

Tracheal injections. — The method of treatment by tracheal injections , 
l^romises much better results, but should only be practiced by a relia- 
ble veterinarian, who can oversee the results and take all necessary pre- 
cautions. The method has been detailed in the Second Annual Report 
of the Bureau of Animal Industry, 1885, page 284. It consists of intro- 
ducing remedies directly into the trachea by means of a hypodermic 
syringe which cause the death of the parasites. The medicines thus 
introduced have an opportunity of acting upon the parasites directly, 
before they are all absorbed by the mucous membrane ot the air pas- 
sages. There is no reason to doubt that they may have even a second- 
ary effect after their absorption if they are naturally thrown off by the 
mucous membrane of the air-passages and the epithelium of the alveoli, 
which is the case with most volatile substances. 

The method of tracheal iujectious waa first tried by Gohier in the early part of the 
present century, after learning experimentally that considerable quantities of liquid 
can be introduced into the trachea without producing suflfocation. Delafond some 



207 

years after conducted some experiments to determine the absorptive power of the air 
passages. He found that mucilaginous decoctions and solutions of sugar or honey 
are speedily absorbed when injected into the trachea, inducing slight symptoms of 
suftbcation for one or two hours. He also found that solutions of narcotic agents 
and stimulants manifest their physiological effects very soon after injection, and that 
oils and oily medicines produce a congestion of the lungs which is but slowly dis- 
sipated, and that even very dilute solutions of mineral and vegetable acids produce 
intlammatiou, with copious secretion of mucus, giving rise to symptoms of asphyxia 
and even leading to death. 

Dr. Levi, of the University of Pisa, has recently applied this method in the treat- 
ment of a number of diseases {Manuel praiique des injections tracheaJes dans le cheval, 
1883). His experiments also tended to show that the mucous membrane absorbs very 
rapidly, and is tJicrofore less apt to suffer from the injection of irritating substances 
than if the absorption were less rapid. He also determined that the injection of small 
quantities of oily substances is not dangerous, the oil probably being emulsitiod and 
absorbed. Finally, there is always a slight reduction in the number of respirations, 
amounting to about three or four per minute, after the introduction of liquids, even 
when distilled water only is injected. 

Without entering into interesting questions concerning the administration of med. 
icines in this manner in other diseases, which are discussed at length in the work 
mentioned, we find that the author has experimented ou but one case of lung worms 
to test the eflicacj'^ of the method. Others, however, have reported cases in which 
their success justifies a detailed account of the method for future application. 

The instrument to be used is a simple hypodermic syringe holding from 1 toy fluid 
drams. The needle of the syringe must be provided with a removable solid rod or 
trocar, so as not to become plugged when it is pushed through the skin and walls of 
the trachea. As the needles are apt to break, a number of them should be kept on 
hand. After the operation the syriugo should be carefully washed in pure water, the 
piston supplied with a drop of olive oil, and the trocar replaced in the needle. 

It is best to disinfect by tilling the syringe and needle with a 5 per cent, solution 
of carbolic acid, or a 0.1 per cent, solution of mercuric chloride* before washing in 
pure water. The disinfection, however, is not absolutely necessary in this operation 
if the syringe and needle be kept thoroughly clean. 

To administer the medicine first fill the syringe and place at the side. Hold the 
sheep for drenching, and extend the head of the animal so as to fix and make promi- 
nent the trachea, which will be felt as a tense elastic tube along the middle line of 
the neck. The most convenient point for the introduction of the needle Is at about 
the middle of the length of the neck. It must be remembered that some care is to be 
observed, as the trachea is near some important structures on either side — the jugular 
vein, the carotid artery, and the pueumogastric nerve. Having fixed the trachea 
with the left hand, the needle with the trocar is inserted beneath the skin, and then 
an interannular space is sought so as not to pierce a cartilaginous ring. Or the 
needle may be pushed directly into the trachea without necessarily avoiding a 
cartilaginous ring. The unimpeded movement of the free end of the needle as if 
in an empty space is a sure sign that the needle is in its proper place. The trocar is no w 
removed, the syringe screwed upon the needle, and the contents very slowly forced 
into the trachea. Before the needle is finally, withdrawn Dr. Levi thluks best to 
wash it out with some pure water so as to remove the injecting fluid. lu withdraw- 
ing the needle this might accidentally be discharged in the wound made bj' the needle 
and set up inflammation if the substauces introduced be irritating. How this wash- 
ing out is to be done he does not state. It seems that a small pipette or medicine- 



* The former is prepared by adding 5 parts by weight of pure carbolic acid to 100 
parts by weight of pure water previously heated ; the latter by adding 1 part of the 
corrosive sublimate (a violent poison) to 1,000 parts of water. 



208 

dropper filled with water and inserted into tlie end of the needle would suflice to wash 
it out, or drawing back the piston of the syringe WMuild leave the needle compara- 
tively empty. The need'e might also be washed out by removing the syringe, wash- 
ing it out, filling with water, and forcing a few drops into the trachea through this 
needle. This, however, would cause unnecessary delay before the animal is released, 
and is therefore not to be recommended. The simi>lest method, then, to empty the 
needle would be to drawback the piston, for the dischargeof anything but the purest 
water into the wound may produce more irritation than the medicinal substances 
themselves. The animal should be watched for some time, especially after the first 
operation, to observe how the injection has been borne, and whether any symptoms 
arise which indicate difficulty of breathing. 

If, as has been suggested, a slight incision be made in the skin before introducing 
the needle, and if a cartilaginous ring be avoided in piercing the trachea, the ordi- 
nary needle with beveled extremity will be suflicient, and the trocar may be dis- 
pensed with. When the needle has entered the trachea, a slight hissing noise, dne to 
the entrance and exit of air with each inspiration and expiration, indicates that the 
needle has reached its destination and is not plugged. 

The substances to be injected should have distinctly vermicide properties, with- 
out being at the same time too irritating or poisonous in their effects on the animal. 
Levi gives two formula' which he used with success upon a sheep. The worms were 
discharged in three days and the catarrh cured : Iodine, 2 parts ; iodide of potash, 10 
parts ; distilled water, 100 parts, by weight. 

Begin with half a dram of this solution, add half a dram of water, and increase 
by half a dram of the above solution each day up to 5 drams. Another remedy is the 
following: Mis equal parts of turpentine and olive oil, and inject from 1 to 4 drams. 
In this case the writer probably intended to state that the dose should be increased 
from 1 to 4 drams on successive days. 

Eloire (Becueil de Med. Vet., 188'A, p. 683) gives the following formula : Ordinary 
oil of poppy and oil of turpentine, each 100 parts; carbolic acid and purified oil of 
cade, each 2 parts. 

The oil of poppy, being a bland oil, does not possess any medicinal proj)erties, and 
may be replaced by olive oil. Each sheep to receive about 2 drams a day for three 
days. 

Six animals treated in this way showed immediate improvement and were finally 
cured. Penhale { Velerinarian, 1885, p. 106) reports immediate relief and ultimate 
cure in two calves by injecting the following mixture : Oil of turpentine, 2 drams; 
carbolic acid, 20 drops ; chloroform, | dram. 

One-half of this amount may be given to a sheep and the dose subsequently in 
creased if necessary. 

Hutton (loc. cit., p. 62) reports favorable results in six out of eight cases by inject- 
ing the above liquid, in which 1 dram of the tincture of opium was used in place of 
chloroform. 

This completes the list of remedies thus far suggested and tried. 
The favorable testimony, though not abundant, is very eacouraging. 
There are many substances, no doubt, the use of which might be more 
beneficial than those mentioned, but nothing can be said of them until 
they have been tested. 

The dose for young sheep should be proportioned to the age and 
size of the animal. The preparations with turpentine seem to have 
given the best results. During treatment the patients should receive 
the best of care. 

The prevention of this disease is very desirable, though it may never 



209 

be completely attained. If a farm is completely free from it in the first 
place, then prevention simply lies in not allowing infected sbeep to be 
brought on the premises. All purchases of sheep should be from flocks 
which have shown no signs of the disease in preceding years. Brooks 
which run from pasture to pasture offer a chance of infection where the 
neighbors' flocks upstream are infected. Strange sheep should not be 
pastured unless they are known to be free from parasites. Feeding 
and care to keep up the general health are essential. Careful separa- 
tion of affected animals should be practiced, and the worst diseased 
ones may be slaughtered. Treatment should not be neglected. During 
treatment it is best to keep the sheep up, and after the course of treat- 
ment is concluded they should be turned into new pastures. 
23038 A p 14 



210 



STKONGYLUS FILARIA, Rud. 

Plate XXXIV. 

Fig. 1. Adult female, x'-^: a, head; h, vulva. 

Fig. 2. Adult male, x3: a, head; b, bursa and epicula. The dark line in Figs. 1 

and 2 is the intestine. 
Fig. 3. Cephalic end : a, mouth ; b, oesophagus ; c, intestine ; d, unicellular glands. 
Fig. 4. Middle portion of female : o, vulva ; b, vagina ; c, c, uteri with develoi^ing 

eggs- 
Fig. 5. Piece of skin showing striae. 
Fig. 6. Spicula: a, the fenestrated chitinous cylinders ; Z>, the bulb like enlargement 

of the surrounding membrane. 
Fig. 7. Caudal end of female : «, anus ; b, b, intestine ; c, loop of the caudal uterus. 

d, ovary. 
Fig. 8. Caudal end of male, ventral view : a, intestines ; i», seminal reservoii ; c, the 

torn edges of the spread bursa; d, ventral costai ; e, ventro-lateral ; /, 

lateral ; g, dorso-lateral ; h, dorsal ; i, spicula. 
Fig. 9. The same lateral view. 

Fig. 10. a, female, natural size ; b, male, natural size. 

Fig. 11. Eggs showing various stages of development of embryo in the foIlowiQg 
ordter : a,b,c,d; e, embryo escaped from shell. 



PLSTE XXXIV 



// 



'P 








z^^- 




\^ 







n 



'ii^'i 



A 



<y 



Haines, del. 



STRONGYLUS FILARIA. 
(The Thread Lung Worm ) 



. & r., j.iii, H.-i 



212 



STEONGYLUS FILAEIA, Rud. 
Plate XXXV. 

Portion of right lung of lamb, dorsal view. The afifected region is the dark col- 
ored posterior end. It is clearly marked off from the healthy portion. The dark red 
spot about the middle of the figure is also caused by the worms, but it is exceptional 
to find these lobes aflected in early stages. 



PLKTE XXXV 








^. 



(^ < 





Haines, del. 



A.Haen & Go. lithacaustic.Balrimore. 



STRONGYLUS FILARIA, 
LAMB'S LUNG AFFECTED BY THREADWORMS. 



214 



STEONGYLUS FILARIA, Rud. 

Plate XXXVI. 

Portion of right Inng of lamb, ventral view. This is the same lung figured in 
Plate XXXV. The affected portion is in the posterior end. The lung tissue has 
heen dissected to show the tracheal branches and the bronchi. The bronchi leading 
to the dark-colored affected region are filled with the life-sized figures of the Siron- 
gxjlus filaria. 



PLffiTE XXXVI 




Haines, del 



kMoen i Co. LIthacaustic.Baltin 



LAMB'S LUNG INVADED BY STR0NGYLU8 FILARIA. 



INDEX. 



Page. 
Abdomen, parasites in (see lAnguatula tmioides and Twnia marginata'). 

Abundance of parasites 9 

Acari 53 

Acariasis 53 

Acarina 22 

Amphistovia conicum 16, 138 

Angora goat louse 50 

Antelope as a bearer of sheep parasites 15 

Arrangement, plan followed in bulletin 22 

Arthropoda 18 

Ascaris lumbricoides 16,145,151 

description 151 

figures 154 

Ascaris ovifi 151 

Ascaris suilla , 152 

Balhiana giganiea 18 

Bladder worms 72 

Brain, parasites in (see Cocnurus cerebraUs). 

Bronchitis, verminous 185,201 

Cixjcum, the worm in 181 

Catarrh, nasal 25 

Chorioptes communis var. ovis 53, 65 

Coccidia _,.. 18,117 

Cocnurus cerebraUs 30,72,83 

Common scab (see Psoropies communis var. ovis). 

Coyotes, worms in 14 

Cysticercus ovis 72 

figures 88 

in mutton.. 87 

Cysticercus tenuicollis 72,75, 117 

figures 80,82 

Definitions 19 

Description of species, contents of 10 

Diagnosis of parasitic diseases 11 

Disease, parasitic, mainly due to mechanical causes 11 

importance of early diagnosis 11 

the nodular of intestines 165 

Bistoma hepaticum 16,17,127,137 

description 127 

disease caused by 129 

diagnosis 130 

duration 130 

pathology 131 

215 



216 

Page. 

Distoma hepaticum, disease period of anaemia 1"29 

cmigratiou 1150 

immigratiou I'iU 

loss of Hesh i:50 

prognosis i:5l 

Bymi)toiii8 12l> 

treatment 133 

figures 130 

legislation concerning 134 

life history 128 

occurrence 127 

rare in United States 17 

Diatoma lanceolatum 16 

description 137 

figures 140 

Dochmiua cernuus 16,17,22,117,118,142,145,146 

description 155 

disease caused by 156 

treatment 157 

figures 160 

life history 155 

occurrence 155 

Doclmiius trigonocephahts 156, 167 

in dogs 155 

life history 155 

Dog, as a beast of prey 14 

as a carrier of dangerous parasites 14 

Dochmiits trigonocephaJus in 155 

legislation concerning 78 

parasites of, common to man 14 

sheep 14 

relation to sheep husbandry 13 

Tcvnia ccenurus in 76,86 

Tamia eucumerina in 76 

Twnia marginata in ^. 76, 86 

Taenia serrata in 76, 86 

tape worms in 14, 75, 76 

intestine 14 

and in sheep 76, 86 

treatment 77 

preventive - 78 

varieties of, liable to infection 14 

Echinococcus (see Tania echinococcus). 

Embryos, conditions necessary for raising 11 

External parasites If^ 

Feeding 1"^ 

Flukes 127,137 

Foot scab 6^ 

Gadfly (see (Estrus ovis). 
Gid (see Tainia ccenurus). 

false 30,38 

Goat lice (see Tiichodtcfex vUmax and T. limbattts). 
Grub in the head (see (Estrus oris). 
Head parasites (see GiHirus oris and Tmiia ccenurus). 
Head scab (see Sarcoptes scabiei). 



217 

Page. 
Hoose 185,201 

Husk 185,201 

Hydatids (see Twnia echinococcus). 

Illustrations 10 

material for 10 

purpose of 10 

Infection, how secured in experiments 11 

Injuries, how efl'ected by parasites 11 

Intestines, nodular disease of 165 

Itch 53 

insects 53 

Lime, parasiticide in manure , 13 

Liiiguatula tivnioides 14, 16, 69 

description 69 

disease caused by 69 

figures 140 

life history 69 

Lingnatnla rhinaria 69 

List of parasites described , 16 

external parasites 18 

Liver, parasites in 127 

Liver rot 127 

Liver tluke (see Distoma hepaiieiim) 127 

(see Distoma lanceolatum) 137 

Lombriz (see Strongyhis contortus). 
Louse fly (see Melophagns oviniis). 

Lung worms 185,186,201 

diagnosis 186 

species of 185 

parasites of the Old World 17 

Lye water and whitewashing in scab 12 

Mallophaga * 45 

Man, parasites of, common to dog 14 

sheep 16 

tape worms in 14 

and in sheep 87 

Manure, destruction of embryos in 13 

economic management of 12 

mixture of, with lime • 13 

source of parasitic infection 13 

Measles, in mutton (see Twnia tenella). 

Measurements, tables 23 

Medical treatment 15 

Melophagua ovinua 16, 39 

disease caused by 41 

treatment 41 

experiments with 41 

figures 44 

habits of 40 

life history 40 

occurrence 41 

source 41 

Muscle, parasites in 87 

Nodular disease of intestines 165 

Nose, parasites in 25 



218 

Page. 

(Esophagostoma acutum .., itjs 

CEsopJiagostoma cohmbianum 16, 17, 20, 21, 22, 118, 145, 161, 162 

description 167 

determination of adult 166 

disease caused by 169 

diagnosis 172 

pathology 169 

prevention 173 

distribution 165 

figures 174, 176, 178, 180 

investigation concerning 165 

life history 168 

occurrence 168 

(Estrusovis 16, 17, 19,20,25,85 

description 25 

of larvae 26 

eifects on sheep 27 

figures 34, 36, 38 

occurrence 30 

pathology 28 

treatment 31 

surgical , 33 

Paper skin 185,201 

Parasites, abundance 9 

animal 17 

common to sheep and dog 14 

external, definition of 18 

destructiveness 22 

how sheep become, infested 19 

length of time of development 20 

location 18 

of the skin 39 

seasonal appearance 21 

vegetable 17 

Parasitic diseases the chief source of losses 9 

Pastures, as a source of infection „ 13 

care of 13 

Pentastoma denticulatum 69 

Pentastoma twnioides 69 

Phthiriasis i 39,45 

Pneumonia, verminous '. 185, 186 

Psoroptes communis, var. oris 16, 17, 53, 56 

disease caused by 56 

diagnosis 57 

differential 59 

pathology 57 

prognosis 58,59 

source of contagion 58 

symptoms of 56 

treatment medicinal 60 

preventive 56 

figures , 66,68 

legislation concerning 64 

Purchasing sheep, examinations in 15 



219 



Eabbits, not infested by parasites of sheep . 14 

Eangcs as a source of infection . 13 

Salting 13 

Scab - 53 

general description of 53 

insects 53 

life history - 53 

white-washing and lye water 12 

Sarcoptesseahid var. ovis 53,54,56 

description 54 

disease caused by 54 

diagnosis 56 

prognosis 56 

source of contagion 55 

treatment 56 

Schroatoma equinum 161, 162 

Sclerostoma hyposiomum 16.145,167,168 

description 161 

figures 164 

life history 161 

occurrence 161 

Sclerostoma tetracantlmm 161, 162 

Sheep grub (see CEstrus ovis). 

Sbeep iudustry, value of 9 

Sheep louse (see Trichodectes sphwrocephalua). 

rod headed 45 

Skiu, parasites of 39,45,49 

Sources of information, recognition of 23 

Species abundant in United States 16 

American and European compared 16 

described 17 

destructive 17 

not in United States 16 

of external parasites 16 

rare in United States 16 

Staggers (see Taenia cosnurus). 

Stomach round worms (see Strongylus contortus). 

Sirongijlus contortm 16,17,20,22,117,118,141,146,202 

description 141. 

disease caused by 142 

treatment 142 

figures 144 

life history 141 

the lombriz disease 141 

Strongylus filaria 16,17,20,21,185 

description 201 

disease caused by 203 

duration 203 

tracheal injections for 206 

treatment, medical 205 

preventive 202,208 

figures 210,212,214 

occurrence 204 



220 

Page. 

Sirongylus fdicoUis 16,22,118,145,146,149,202 

description 146 

figures 148 

Sirongylus mivutisBimus in Algeria 17 

Strongjjlus ovis-inamonaUs 16,17,20,22,185,186,201,204 

description 186 

disease caused by 187 

diagnosis 187 

pathology . 187 

prognosis 187 

source of infection 189 

treatment medicinal 190 

preventive 189 

figures 192, 194, 196. 198,200 

life history 186 

Strongylus rtifescens a synonym 17 

Strong ijlus ventricosus 17,22.118,145,149,202 

description 149 

figures 50 

new parasite of sheep 17 

Sturdy 83 

Symptoms of sheep infested with parasites 11 

Taenia aculeata 89 

Tamiaalba 89 

Tcenia Benedeni 8:^ 

Tain ia centripunctata 89 

Tcenia coenurus -. 14,16,17,19,22,72,76,83 

cystic stage 83 

disease caused by 89 

diagnosis 85 

duration of development 84 

treatment 85 

figures 86 

life history 83 

method of infection 85 

Tamia cucumerina 76 

Tcenia echinococcus 14, IG, 17,72,86 

figures 8S 

in man 14 

life history 86 

treatment 86 

Twnia expansa 16,17,20,103,113,142,202 

description 11'5 

disease caused by 11-' 

diagnosis H'' 

duration 120 

occurrence 120 

prognosis -- H-' 

treatment 120 

distribution 16,17,103,11:! 

experiments with 116 

figures 124, 126 

life history 116 



221 



Tcenia expansa life history summary , 118 

occurreuce 1]5 

Tcenia Jimiriata j^ 17 89 

description , 91 

disease caused by 95 

treatment, medicinal 98 

preventive 100 

distribution 93 

— experiments 103,105,108 

figures 110,112 

t investigations concerning 90 

life history 94 

objects of experiments 9I 

occurrence 93 

2>os<-7>io/<t;m examinations for finding 103 

results of experiments 91 

Twnia Giardi 89 

Tania globipunctata 39 

Tamia marginal a 14,15,16,19,20,22,72,83,86,114,117 

cystic stage 72,103 

disease caused by 72 75 

diagnosis 76 

treatment 77 

distribution 72 

figures 80,82 

in man 14 

legislation concerning 73 

life history of adult 75 

occurrence 76 

Ta'/nia ovilla 89 

Twnia ovipunclata 89 

Tamia plicata, wrongly identified iu sheep 89 

Twnia serrata 7g gg 

Twnia tenella ' ig 72 37 

figures ' 'pg 

in man 87 

Twnia Vogti 89 

Tape- worm, adult (see Twnia finibriata and T. txpansa). 

disease (see Twnia fimbriata and T. expansa). 
immature (see Twnia marginata, T. cwnurus, T. echinoeoccus, 
and T. tenella.) 

occurrence .., ___^ 72 

in dogs 75 

in European sheep 89 

the broad Hq 

fimbriate 89 

Tracheal injections 206 

Treatment, empirical 12 

hygienic 12 

medical, of large flocks 12 

Irichocephalus affinis 16,22,117,118,142,145,181 

description I81 

disease and treatment 182 

figures „_. 184 



